syxlette, praising someone who dislikes jumping will produce the behavior that you described, so be aware of that and just pick them up and put them back to what you want them to be doing. They still benefit from the praise, but because they dislike jumping, they get stuck, since their reaction to praise involves jumping.

Jenny is correct, though, that you can't make them clean up after a meal, since dropping them on the table when there is food present will cause them to sit down and eat. They must clean up on their own.