A 5x5 grid just sounds silly. Hell, a 4x4 grid is a bit of a stretch as not much could be made with it that wouldn't work on a 3x3. Hardly anything in the game (except, perhaps, user additions in the future) should require anything beyond a 3x3 grid (or MAYBE a 4x4).
or leave the craft table as-is and make a more advanced version
And 5x5 crafting blocks have been suggested a million times.
and a 5x5 would allow for more creativity for crafting recipies