What did Walter pour all over his food?

Walter poured molasses all over his food.

Walter interrupted to ask if there was any molasses in the house. Atticus summoned Calpurnia, who returned bearing the syrup pitcher. She stood waiting for Walter to help himself. Walter poured syrup on his vegetables and meat with a generous hand. He would probably have poured it into his milk glass had I not asked what the sam hill he was doing.

I always thought it was to camouflage the taste; a habit he acquired as part of a poor country family that often ate wild game, such as squirrels and possum, which has a very gamey, wild taste.