When I had my table built, I also had the manufacturer build a 3-piece table-top out of the same wood of which the table was constructed (I use my dining room for a pool room, so I occasionally need a buffet table when people are over).
While it's a bit on the heavy side (it's best to have two people place the sections to avoid damage to the table- these sections are solid wood), the edges that contact the table are lined in felt, there are pegs that lock the pieces together, and it looks really nice and fits perfectly (though I always put a plastic tarp over it in case any liquids are spilled).
I paid just under $300- I would imagine it would cost quite a bit more in the States.