By different size do you mean thickness?
More details or photos.
If they are different thicknesses, you'll need to put luann or 1/4" plywood underneath to make it level. You will probably need to piece them together with some 1 x 2…if they are the same size, you might could just lay them down on a piece of plywood and glue or screw them down from underneath. Good luck!
Very much possible. We use parametric CAD/CAM software Xcab to design coffee tables, Side tables and dinning tables e.t.c. Then we optimize the parts and precisely Cut the boards on a SCM CNC routing and drilling centre. easy-peasy.