Recreate the ASCII-table as an ASCII-table
Python 2 3.6, 185 183 175 159 156 bytes

Saved 8 bytes thanks to FlipTack!

Still quite new to golfing in Python.

for a in["Dec  Chr   | "*3,"-"*39]+["".join(f"{l:&lt;5}{('Space',chr(l),'DEL')[(l&gt;32)+(l&gt;126)]:&lt;6}| "for l in(i,32+i,64+i))for i in range(32,64)]:print(a[:-5])


Uses a nested list comprehension to generate the table body.

Ungolfed:

lines =   \
  ["Dec  Chr   | "*3, "-"*39] +                      # first two lines
    ["".join(                                        # join 3 parts of each line
      f"{l:&lt;5}{('Space',chr(l),'DEL')[(l&gt;32)+(l&gt;126)]:&lt;6}| " 
        for l in (i,32+i,64+i)                       # generate 3 parts of a line
      )
      for i in range(32,64)]

for line in lines: print line[:-5]


Update: apparently using f-string here is shorter than the % operator.



Old attempt, 185 183 175 bytes

print("Dec  Chr   | "*3)[:-5]+"\n"+"-"*34
a=lambda x:('Space',chr(x),'DEL')[(x&gt;32)+(x&gt;126)]
for l in range(32,64):print("%-5d%-6s| "*3%(l,a(l),l+32,a(l+32),l+64,a(l+64)))[:-5]


Ungolfed:

print ("Dec  Chr   | "*3)[:-5] + "\n" + "-"*34
def a(x):
    return "Space" if x==32 else "DEL" if x==127 else chr(x)
for line in range(32,64):
    print ("%-5d%-6s| "*3 % (line, a(line), line+32, a(line+32), 
      line+64, a(line+64))) [:-5]