Your Language in a Box
Python, 1342 / 349 = 50.02

If I have understood the rules correctly, this should be a valid submission.

from sys import *
stdout.write("""   ABCDEFGHIJKL
  ##############
1 #from   f  i #
2 #  r   not t #
3 #      write #
4 #  s   import#
5 #  y   False #
6 #  stdout    #
  ##############
A1 from 4+5
C1 or 2+5
H1 format 6+25
K1 iter 4+10
G2 not 3+5
G3 write 5+10
C4 sys 3+5
G4 import 6+10
G5 False 5+5
C6 stdout 6+10
TOTAL 134
""".format(not False or iter([])))


You can really just keep incrementing your score by adding more identifiers: the size of the program increases linearly (by approx. twice the identifier length), while the score increases approximately by the square of the identifier length. Then the challenge becomes more how to cram most keywords into the square instead of how to write a short program to do it.