Operant conditioning?

"It is a dog’s natural inclination to avoid the leaders of the pack when the leaders are eating. Not doing so in a real pack situation is a good way to get bitten. If your dog sees you as the boss, it will treat you with this same respect.

However, even dogs that normally are respectful can easily be taught to beg at the table. All you have to do is occasionally give them a sample from your plate. Presto. A beggar is born.

The solution? Never feed a dog from the table. It’s a hard behavior to control once started. So don’t start. And don’t let anyone else start, either. It’s really that simple. Start the holidays with well-behaved pets. Keep it that way by not feeding them from the table."