So update on this table. Since this was one of my first projects, I had limited tools and experience. I never glued anything and I didn't seal the underside of the table top. The breadboards stick out about an inch on each side and the middle planks are very cupped and warped.
I am in the middle of redoing it. I found some really nice lumber at Menards if you can believe it. I ran all the boards through my table saw, which I didn't have back then, so they are all flush with each other and there are no grooves. I used glue this time. Filled in with wood filler where needed. I then sanded the hell out of it with my belt sander, which I should have done the first time. Now it looks like one solid piece of wood. Just have to put one or two more coats of poly on it yet.