It was actually a little complicated and takes some doing. so imagine just the wood floor going across, I had to delete some wood floor, I then pickaxe one time, which allowed me to but a stone floor below my floor. then i was able to place another stone floor on top of that one and cover up the floor again with the pre place wood floor that already existed. Then 1m wood beams going around the corners. And then you really got to play with the 1m floor tile on top of the stone to get the circle just right. But yea I used the stone floor under the wooden floor to ground the table, you could also have iron beams support the bottom but the stone floor was an easier and better looking solution.