Honestly, if he's at the table and not actively eating, then he's probably done, and I'd let him get down. Maybe put a few toys nearby the table and let him play where you can keep an eye on him, while you finish your meal. With my kids, as soon as they started acting silly and playing instead of eating, they were done and I put them down. If they're really hungry, they'd be eating. That might be as short as three to five minutes at that age. It doesn't take them long to learn that if they want to eat, they have to eat, and not play.
It really is normal for that age. They're not pushing the limits intentionally. They haven't actually learned the limits yet, and they don't have the self-control to respect those limits even if they know them. You have to repeat it thousands and thousands and thousands of times before they get it. You'll probably start seeing an improvement in "civilized mealtime behavior" by the end of the next year, if you keep gently guiding his behavior. In the meantime, keep your expectations realistic-- once the playing starts, the meal is over for him, even if he's only just sat down.
me , he , my three , , and -- and the one we lost