Tabletop Simulator is still a work in progress, being sold under the "early access" program. There are already several game modes for things like chess and poker, but honestly I think there is more usable software for those games. Users have been creating custom content (or adapting Vassal modules) for several boardgames, and there is the option of using it as a "sandbox": just a plain table where you can place a board and pieces as you wish, and move them around.
My expectation is to be able to set up and play wargaming scenarios in full 3D. In the best case, playing it with an Oculus Rift or similar device, it might get close to a real tabletop experience... the reality, however, is still a bit far from this. Only recently, a (very rough) measuring tool has been added to it, and there is no convenient way to measure movement distances or even mark movement paths. There is no support for moving formations of figures, and as far as I know the custom table has a fixed size -- so there is no way to set up some great 6'x8' tables for instance.
It is possible to import custom models or even make figurines that look like paper stand-ups, but the mechanisms are clunky and limited. For instance, the stand-ups have 1.5" round bases. If you want other sizes, you have to scale them down manually, a process that involves trial and error and is tiresome.
As the program is still under development, I have hope that the missing features will be added with time. For now I might try to set up a spaceship combat game or something else with small number of models, grid-based movement and limited board size...