What does Atticus find in the Kitchen? Who gave all of those things to the family? And why?

Calpurnia asks Atticus to look in the kitchen at all the food the Negro community has sent, "You better step out here and see what's in the kitchen, Mr. Finch." Atticus is touched but know people in the black community will go hungry because of this. He instructs Calpurnia to tell them to never do this again.