what is Walter Cunningham like? what does his behavior during lunch suggest of his home life?

Walter asks for some molasses and proceeds to pour it all over his meat and vegetables. Scout rudely asks him what he's doing and Calpurnia gives her a lecture in the kitchen about how to treat guests - even if they're from a family like the Cunninghams.

"By the time we reached our front steps Walter had forgotten he was a Cunningham. Jem ran to the kitchen and asked Calpurnia to set an extra plate, we had company. Atticus greeted Walter and began a discussion about crops neither Jem nor I could follow. “Reason I can’t pass the first grade, Mr. Finch, is I’ve had to stay out ever‘ spring an’ help Papa with the choppin‘, but there’s another’n at the house now that’s field size.” “Did you pay a bushel of potatoes for him?” I asked, but Atticus shook his head at me. While Walter piled food on his plate, he and Atticus talked together like two men, to the wonderment of Jem and me. Atticus was expounding upon farm problems when 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."