Why does joe think that pip has been bolting his food?

Pip knew that he was going to meet the man in the marshes later that night. The man wanted food and Pip was smuggling it out of the house, "His eyes looked so awfully hungry, too, that when Pip handed him the file it occurred to him he would have tried to eat it, if he had not seen the bundle."

Oops, I guess I really didn't answer that! Joe goes on about how he used to bolt food and says he won’t tell. I'm thinking that you are right. Mrs. Joe thinks it has something to do with his sister's cooking not being that great. Mrs. Joe hits Pip with the "tickler" so she obviously has taken offence of some kind.