Walter Cunningham is a schoolmate invited over for lunch by Jem after Scout roughs him up a bit at recess. Walter is a very poor son of farmers who have been hit hard by the Great Depression. He is not used to eating on a daily basis, so when he is presented with meat and vegetables at Scout's house, he asks for syrup and drenches his plate with it. Scout screams and asks what he thinks he is doing, and it is at this point that Calpurnia tells her to go into the kitchen. The lecture that Scout gets involves how one should act as a hostess when company is over.
According to the lecture, one of the first rules of the guest-host relationship is not to comment on or criticize the guest's eating habits. Calpurnia says that if a guest wants to eat the tablecloth, the host should let him. Scout is only six years old and doesn't know any better, but Walter was embarrassed beyond anything Scout could feel from being put in her place at this point. The guest always comes first. In addition, it isn't Scout's place to tell anyone else how to live, especially if they aren't as well-off as she is. Calpurnia's lecture is as follows:
"Hush your mouth! Don't matter who they are, anybody sets foot in this house's yo' comp'ny, and don't you let me catch you remarkin' on their ways like you was so high and mighty! Yo' folks might be better'n the Cunninghams but it don't count for nothin' the way you're disgracin' 'em—if you can't act fit to eat at the table you can just set here and eat in the kitchen!" (25).
In Chapter 3, Scout rudely calls attention to the table manners of Jem's guest, Walter Cunningham. Calpurnia scolds Scout telling her that when people differ, Scout is not “called on to contradict ‘em. . . .” She also tells Scout that guests in her home should be treated guests, no matter how different they are. Calpurnia is trying to teach Scout to treat people equally, not on the basis of their wealth or lack of it. This foreshadows the lesson about race that Atticus will try to teach the town when he defends Tom Robinson.