table manners

In the book "Parenting By God's Promises" Joel Beeke emphasizes repeatedly how important it is for a family to take time and have supper together. This should be a time of asking each child how their day was and a time of conversing kindly and showing interest in one another.

Adam is very good at this and sets a good tone during supper time. I am the problem. By supper time I am tired and I have a hard time being nice when I have the twirling, chewing whirlwinds sitting all around me. To the right of me I have a boy that chews his food like a cow. The food on his plate is stuffed into his mouth in three humongous bites. There is no way that his lips could seal closed with his cheeks already bulging. I also have a climber right beside me stuck in a highchair. When he feels full he just throws his plate with the left over food on to the table. I was never good at catching things, so a plate of food is impossible to catch and lands all over the floor. To my left I have a boy that can twist and turn his body into all sorts of positions. I spend so much of the supper time reminding him that he is not a monkey and that he must sit on his behind. The boy that sits across from me is lucky because he is out of my reach. He has table manner issues too. He thinks that a fork is a foreign object and that somehow each particle of food should be felt with his hands first before his hands put the food into his mouth. On top of that he has a habit of moving his chair further and further away from the table. I think that he does this on purpose since he is our most picky eater. A good portion of his food just happens to fall onto the floor.
(Adam sits right across from me and just so you know he has good table manners!)
I look around me and wonder is this just a boy thing? Do girls automatically come with good table manners or do they need to be taught too? I imagine my sons' future girlfriends going out on a date with one of them and saying "Where is this guy's manners? They are despicable! Didn't their mother teach them anything?"
So should I leave the table manners teaching alone and be like Adam and concentrate on creating a good family atmosphere? Is this just a stage and all of a sudden the child develops table manners on his own?
 My conclusion is that just like the rest of life, balance is the best thing. The challenge is finding it. It also doesn't hurt to ask other families how their supper hours go and maybe they have some helpful suggestions. Maybe some of you have some suggestions too!