I have several that like people food and beg for it. Some like potato chips, some like buttered bread, some like meat, and some like cheese. Josh will eat darn near any crumb that hits the floor!

My solution is to make them sit (yes some cats can be taught to do this on command like a dog) and they have to have all 4 on the floor and sit quietly before they get anything. I also tend not to give them much when I'm actually eating if they're being really bad, and just save a few snippets to give them after I'm done eating. That way they're less likely to associate getting the snack at the same time the people are eating.