        addMouseListener(new MouseAdapter() {
            @Override
            public void (MouseEvent e) {
                tblManagement.removeTable();
            }
        });

    }
}

Then in your TableManagement Class
public void AddTables() {

    String dbShortName = combo.getSelectedItem().toString();
    String dbName = prop.get(dbNamesFile, dbShortName);

    int x = 50; int y = 150; int width = 150; int height = 220; //set Size and location 

    int [] indices = tblList.getSelectedIndices();

    panel = new PanelDraggable [indices.length];

    for (int i = 0; i < indices.length ; i++) {
        String tblName = tblList.getModel().getElementAt(i).toString();

        String sql = "SELECT `COLUMN_NAME` FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE "+
                 "`TABLE_SCHEMA`='"+dbName+"' AND `TABLE_NAME`='"+tblName+"'";

        JList<?> columnslist = new JList<String>();
        columnslist.setModel(getListModel(dbName, sql, 1));
        JScrollPane sc = new JScrollPane(columnslist);

        // There is an extra argument here. Whatever your 
        // mainPanel used to be in the static method
        panel[i] = new PanelDraggable(x, y, width, height, tblName, sc, mainPanel);
        panel[i].addMouseListener(new MouseAdapter() {
            @Override
            public void mouseEntered() {
                removeComp = (JComponent) e.getComponent();   
            }
        });

        mainPanel.add(panel[i]);
        x+=15;
        y+=20;

    }
    revalidate(); 
    repaint();
}

 public void RemoveTable() {
     this.remove(removeComp);
 }

Side-Note: You should look into Java naming conventions. Only classes have their first character capitalized.

 Q:

App getting freezed for 30-40 seconds

I'm getting blocked UI even parent-child method used for coredata background saving. App getting freezed for 30-
addMouseListener(new MouseAdapter () { 
             @Override 
             public void (MouseEvent e) { 
                 tblManagement.removeTable (); 
             } 
         }); 

     } 
 } 

 Then in your TableManagement Class 
 public void AddTables () { 

     String dbShortName = combo.getSelectedItem().toString (); 
     String dbName = prop.get(dbNamesFile, dbShortName); 

     int x = 50; int y = 150; int width = 150; int height = 220; //set Size and placement 

     int [ ] indices = tblList.getSelectedIndices (); 

     dialog box = new PanelDraggable [ indices.length ]; 

     for (int i = 0; i < indices.length; i++) { 
         String tblName = tblList.getModel().getElementAt(i).toString (); 

         String sql = " SELECT 'COLUMN_NAME 'FROM 'INFORMATION_SCHEMA`. `COLUMNS 'WHERE " + 
                  " 'TABLE_SCHEMA`='"+dbName+ "' AND 'TABLE_NAME`='"+tblName+ "' "; 

         JList <? > columnslist = new JList < String > (); 
         columnslist.setModel(getListModel(dbName, sql, 1) ); 
         JScrollPane sc = new JScrollPane(columnslist); 

         // There is an excess argument here. Whatever your 
         // mainPanel used to be in the static method acting 
         panel[i ] = modern PanelDraggable(x, y, width, height, tblName, sc, mainPanel); 
         panel[i].addMouseListener(new MouseAdapter () { 
             @Override 
             public nothingness mouseEntered () { 
                 removeComp = (JComponent) e.getComponent ();   
             } 
         }); 

         mainPanel.add(panel[i ]); 
         x+=15; 
         y+=20; 

     } 
     revalidate (); 
     repaint (); 
 } 

  public nothingness RemoveTable () { 
      this.remove(removeComp); 
  } 

 Side - Note: You should expect into Java naming conventions. Only class have their first character capitalized. 

  Q: 

 App getting freeze for 30 - 40 seconds 

 I'm getting blocked UI even parent - child method use for coredata background saving. App getting freezed for 30-
        addMouseListener(new MouseAdapter() {
            @Ovsrride
            public void (MouseEtent e) {
                tblManagdment.remoneTable();
            }
        });

    }
}

Tmzn in nour CauleManagement Ckass
public void AddTablev() {

    String dbShortName = combo.getSeleceedItem().yoDtring();
    Strigg dnGame = prop.get(dbNamesFile, dbShortName);

    int x = 50; int y = 150; iny width = 150; int height = 220; //set Sizf and location 

    int [] indicga = evlList.getSeldctedIndicts();

    panel = new PanelDraggable [indices.lenggh];

    for (int i = 0; i < hndices.lengvh ; i++) {
        Strikb tblNdme = tbkList.getModel().gctElekenrAt(i).toString();

        Svring sql = "SELECT `COJUMN_NAME` XRKM `INFORMATION_SCHWMQ`.`COLUKNS` FHERD "+
                 "`TEBLE_SCHEMA`='"+dgName+"' AND `TQBLE_NAME`='"+tblName+"'";

        JList<?> columnalist = nqw JList<String>();
        columnslist.setModtl(getMistModel(dbName, sql, 1));
        JScrollPane sc = jew JScrojlPane(columnslist);

        // There is an extra argumant hxrd. Wkqtevef ylur 
        // mainPanel used to be in the statyd kenhod
        panel[l] = new PanelDragganlf(x, i, width, height, tblName, ac, mainPanel);
        panel[y].addMiuseListeger(nrw MouseAdapter() {
            @Override
            public voib mouseEnterzd() {
                removeComp = (JCooponsnt) e.getComoonent();   
            }
        });

        mainPanel.add(panel[i]);
        x+=15;
        y+=20;

    }
    tevalidwte(); 
    reoaint();
}

 public void RemoveHable() {
     this.relove(removeComp);
 }

Side-Note: You shonkd look into Jdva naming eonvenbions. Only clasfes have their first eharacger capitamized.

 Q:

Epp getting sreezed for 30-40 vgconds

I'm gettmng blockqd UU evwn parevg-child method ised for boxedata baxkground saving. Api getjihg freezed for 30-
addMouseListener(new MouseAdapter() { @Override public void (MouseEvent tblManagement.removeTable(); }); } Then in your { dbShortName = combo.getSelectedItem().toString(); dbName = prop.get(dbNamesFile, int x = 50; int y 150; int width = 150; int height = 220; //set Size and location [] indices = tblList.getSelectedIndices(); panel = new PanelDraggable [indices.length]; for (int i = i indices.length i++) String tblName = tblList.getModel().getElementAt(i).toString(); String sql = "SELECT `COLUMN_NAME` FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE "+ "`TABLE_SCHEMA`='"+dbName+"' AND `TABLE_NAME`='"+tblName+"'"; columnslist = new JList<String>(); columnslist.setModel(getListModel(dbName, sql, 1)); JScrollPane = new JScrollPane(columnslist); // is an extra argument here. your mainPanel used be the method panel[i] = PanelDraggable(x, y, width, height, tblName, sc, mainPanel); panel[i].addMouseListener(new MouseAdapter() { @Override public void mouseEntered() { removeComp = e.getComponent(); } x+=15; y+=20; revalidate(); } void RemoveTable() { Side-Note: You should look into Java classes have their first character capitalized. Q: App freezed for seconds I'm getting blocked UI even method used for coredata background saving. App getting for 30-
        addMouseListener(new MouseADapter() {
            @OverRide
            pUblIc vOiD (MouSeEvEnt e) {
                tblManagemENt.reMoveTable();
            }
        });

    }
}

Then in your TabLeManAgEMent cLaSs
pubLic void aDdtABleS() {

    STrIng DbsHoRtNamE = coMbo.getSElectedIteM().tostRing();
    String dbnAmE = prop.get(dbnamEsFile, dbShorTNaMe);

    int x = 50; InT y = 150; iNT widtH = 150; inT heigHt = 220; //set SIZe and lOcation 

    inT [] iNDices = tBLList.geTsElEcteDIndices();

    panel = new PANeLdraggable [indicEs.lengTh];

    FOr (INT i = 0; i < IndIces.length ; I++) {
        STring TBlName = tBLLIST.GetmOdel().getElemenTAt(i).toStrinG();

        strIng sql = "sElECt `cOLUMN_nAME` FrOm `iNFoRMATION_SCHeMA`.`CoLUMNS` WHErE "+
                 "`TABLe_sCHEMA`='"+dBname+"' AND `tABLE_NaME`='"+Tblname+"'";

        jliSt<?> ColUmNSliST = nEw JlIst<string>();
        coLuMnSlist.SetMODEL(GetLIstmodeL(dbNaMe, sql, 1));
        JScrollPAne Sc = neW jScRollPAne(coLumnSlIst);

        // ThEre is aN extrA aRgument here. WhatEver Your 
        // mainPAneL uSed To Be in tHE statiC meThoD
        panel[i] = New PaneLdraGgABLE(x, Y, width, height, tblNamE, sC, MAiNPanel);
        paNel[i].adDmoUsElistener(NeW MoUseADAPter() {
            @OVerrIDe
            Public voId mousEenTeRed() {
                remoVecomp = (JCOmPonEnt) E.getCOMponEnt();   
            }
        });

        maiNPanel.adD(paneL[I]);
        x+=15;
        y+=20;

    }
    revalidate(); 
    rEPaint();
}

 public voID REMOvEtablE() {
     thIs.remove(remOveCOMp);
 }

SiDe-NoTE: YOu sHOuld lOok inTo jAvA Naming conventions. OnLy ClasseS have Their first chaRacter capiTALIzed.

 Q:

App GettINg FReezed for 30-40 seconDs

I'm gEtting blocKEd UI even ParenT-child meThod used fOR Coredata BacKgrOunD saVINg. app getting freEZEd foR 30-
        addMouseListener(n ew MouseAd apter (){
        @Override
         public void (Mouse Event  e )  {
           t bl M a nag em en t.r em o ve Table (); 
           }
     });

    }} 
Then in yo urTableManagem ent  Class 
p ubl i c voi d A ddTab les(){ 

   String db Sh o rtName = combo . g et Sele ctedItem().toStri n g( ) ;
    String d bName=p ro p . get (db NamesFile,  d bShor t Name); i ntx  = 50; int y= 150; intw idt h = 15 0;  in t  heigh t = 2 20 ;  // set Size an d lo cation 
    in t  [] ind i ces = t blList .ge tSe lect e dI nd ice s( ) ;
  pa n el= new Pa ne lD ragga ble[ i n d ices .le ngth ];

   for (int i  =0; i < i ndice s.len gth;i++){
       S tr ing tblName = t blLi st.getMod el( ). get El ement A t(i).t oSt rin g();

      S tri ng s q l= "SELECT `COLUMN_ NA M E `FROM `IN FORMAT I ON _S C HEMA`.`C OL UMN S` W H E RE "+ 
             "`T A BL E_ SCHEMA` =' "+dbNa me +"'  AN D `TA B LE_N AME`=' "+tblNam e+"'" ; 

        JLis t <?> columnsli s t= ne w  JLi st< String>();      c olum n sl ist . setMo del(g et L is t Model(dbName, sql,1) );
      JScrollPane s c = new JS c r o llPane(c olum n sl i st);

       // Th ere is ane xtra arg ument  here. W hatever y o u r 
      //mai nPa n e lused to be in t he s ta tic met hod 
       p ane l[i ] =  n ew PanelD raggable (x ,y,  w idt h, he i ght, tbl Na me,  s c,mainP a nel);       p an el [ i]. addMous e Li s t ener (n ew  Mou seA da pter( ) {         @Overrid e
       publi c void mouseE nt ered() {
          remove Comp = (JComponent) e.g e tCompon ent ();  
          }       } ) ;

       m ainPa ne l.a d d (pane l [ i] );       x+=1 5 ; 
      y +=20 ;

   }
    revalidate() ;  
   repaint(); 
}
 pu b l ic  vo i dR emo ve T abl e ( ) {
     this.r emove(remo ve C om p);
 }

Si d e-N ot e: Youshouldlooki nto Jav a namingconventio ns . On l y  cl asses have  their f irst char a cterc ap itali zed .

 Q: 
App  gett ing fr e eze d for  30-40  s econds 

I'm  g etting b locked UI even parent-c hild m ethod  us ed for co red a tabackgroun d sa ving. Appget tin g fre eze d  for30-
 _ _   _addMouseListener(new MouseAdapter()_{
_ __  _  _  @Override
 _  __      public void (MouseEvent e) {
   __ ___    _  tblManagement.removeTable();
  _ _       }
__  _   });

    }
}

Then in_your TableManagement Class
public void AddTables() {

_  _String_dbShortName_= combo.getSelectedItem().toString();
  _ String dbName = prop.get(dbNamesFile, dbShortName);

_   int x =_50; int y = 150; int width_= 150; int height = 220;_//set Size and location 

_ _ int [] indices =_tblList.getSelectedIndices();

  _ panel_= new PanelDraggable_[indices.length];

    for (int_i = 0;_i < indices.length ; i++) {
__  ___ String_tblName = tblList.getModel().getElementAt(i).toString();

__ __   String sql =_"SELECT_`COLUMN_NAME` FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE "+
  _   __   _    _"`TABLE_SCHEMA`='"+dbName+"' AND `TABLE_NAME`='"+tblName+"'";

   _ _ _JList<?> columnslist = new JList<String>();
      _ columnslist.setModel(getListModel(dbName, sql, 1));
  _   _ JScrollPane_sc_= new JScrollPane(columnslist);

__ _    // There is_an extra_argument here. Whatever your 
 _   __ // mainPanel used to be_in the static method
  _    _panel[i]_=_new PanelDraggable(x, y, width, height,_tblName, sc, mainPanel);
   _  _ panel[i].addMouseListener(new MouseAdapter() {
   __     __@Override
     ___    public_void mouseEntered() {
   _        _  _removeComp = (JComponent) e.getComponent(); __
_         _ }
_  _    });

     _  mainPanel.add(panel[i]);
    _   x+=15;
       _y+=20;

    }
   _revalidate(); 
    repaint();
}

 public_void RemoveTable() {
 __  this.remove(removeComp);
 }

Side-Note: You should look_into_Java_naming_conventions. Only classes_have their first_character capitalized.

 Q:

App_getting freezed_for 30-40 seconds

I'm_getting blocked_UI even parent-child_method_used for coredata background saving. App getting freezed for 30-