Why wont SSMS remember my tables when I connect to the server
You can refresh the IntelliSense cache with the key shortcut:


  ctrl+shift+r


Your query window might have lost its connection as well - just: 


  Right click on the query window > Connection > Connect


As a little extra: This stackOverflow post discusses custom keyboard shortcuts in ssms - there's loads of custom shortcuts you can setup for anything you might need (in ssms the menu is Tools > Options > Keyboard)