Is this the one? It's a tree skirt but you could sew the edge to make it a round table topper (I think people usually applique a circle in the center).
http://www.sulky.com/project/treeskirt/
The pattern is free but you do need a wedge ruler. I am just finishing mine...LOVE IT! Will post pictures in a few days.
The wedge rulers typically come with a pattern or two.