I wouldn't use any type of marble topped table with 3 young boys. In my experience, the table will be used for many activities as they grow - craft projects, eating, games, drinks, etc. Marble does stain and etch. I also think that since you have the space for it, you might want a round table with a leaf or two. You can use it without the leaf everyday, but when they have friends over and you don't want them all in a formal dining area, it's nice to have a table that will expand.

They also come with wood or painted tops.

I would not want an elongated oval one with young kids that may lean on it.