The reason table A requires more force to move, despite being the same size as table B, is that Table A has a greater mass than table B.
Weight is the force that gravity exerts on an object, which is directly related to its mass. If table A has more mass, it will have more weight, requiring more force to overcome its inertia and move it. The other options about density and volume do not directly relate to the force required to move the tables in the context given, as they are said to be the same size.