I actually prefer no rug at all under a table that used often. Seems like it only makes more work and covers up a beautiful floor in the process. We have thick felt pads with a somewhat sharp ring to pound into the bottoms of the legs of the table and chairs that protect our oak floors. They are available at Home Depot, Lowes and even Wal Mart has them in their hardware department.

My personal preference is to not worry about protecting the wood as 'normal wear and tear' is OK and expected. But you will have to refinish quicker than if you protected the floor. I can't imagine putting vinyl on wood, it just would seem like one of those mats you put under high chairs? Of course it is probably different than I am imagining??

I'd leave it naked. As for crumbs, you can get a dog. Oh, but then you'll have to worry about the dog because they really scratch wood floors up!!