A.B.
When my 2nd son was that age, he was into EVERYTHING and was always underfoot. When I would cook, I'd give him pots and pans, and if I had a free second I'd help him "play the drums" on them or give him one of his spoons so that he could cook too. I tried the highchair thing with my son and it didn't work so well. He didn't like to be confined to the chair unless it was time to eat.
I also found the crock pot to be a life saver. I would throw something in either in the morning or when he would take a morning nap, and then not worry about it for the rest of the day.
The cupboard was another trick that did wonders for us. I kept his cupboard empty and he would hide in it while we played "hide-and-seek" or "peek-a-boo" between washing dishes or while I was cooking. If he got ahold of towels or mixing bowls he would stash them in his cupboard, which he thought was great to "hide" them from Mommy.
Good luck!