I have tried SOOOO many things with Jasper, uncluding making him lay down the whole time, which only worked for me, and if other people were eating he would be in their faces, I also tried a spray bottle when he was begging, and also other things.

I just recently started this other thing, that seems to be working quite well, I dont know if its a good idea, I just randomly thought of it, but its been working so its worth a try. Have a plate/bowl of something he doesnt like, or something sour/bitter on the table and whenever he beggs or wants your food, give him the other thing, Jasper got so fed up, that he walked away from the table and left us alone, for the first time ever!

I know it might seem as if your rewarding begging, but rewards are suposed to be something they like