The only way to stop that behavior is to not give in. If you want to give her something, put it in HER food dish, not directly off your plate. Our Starr (RIP) was spoiled this way and would bark and jump 3 feet in the air while we were at the dining room table
We just didn't know any better at that time. With these girls, I refused to have them act this way and forbid anyone from giving them anything at the table. My husband decided to start sharing his evening bowl of cereal with Izzy, in bed, and now whenever he is eating something she begs from him, gets in his face
She knows better with me, and won't bother me when I eat
You just have to stay strong and not give in. Make her wait until you are finished and THEN put a tidbit in her bowl. Be careful what you're giving as well, not too much fat, salt, or sugar.