what the grid keys?
Grid keys are options in coh2 (I think) gameplay options that change all your abilities from their "random" buttons into these buttons :
qwer
asdf
yxcv
Depending on their position in command menu, so every ability in upper row will be qwer depending on its positions in that row, the same apply for second and the same for third.
This for example gives all your grenades same control button (Y or Z depending on if you use qwertz or qwerty) no matter what kind of grenade you are using because all grenades are in lower left corner.
It is also easier to navigate, you just look at panel and you see what key you should press and they are all located on left part of keyboard instaed of normal keys, whitch are everywhere