jmc

Only the number of lamps on each table matters, so we can list the possibilities systematically: $$\begin{array}{rl}(& 10,0,0)\\ & (9,1,0)\\ & (8,2,0)\\ & (8,1,1)\\ & (7,3,0)\\ & (7,2,1)\\ & (6,4,0)\\ & (6,3,1)\\ & (6,2,2)\\ & (5,5,0)\\ & (5,4,1)\\ & (5,3,2)\\ & (4,4,2)\\ & (4,3,3)\end{array}$$There are a total of $\boxed{14}$ possibilities.