This is a furniture so can be added to any room or openspace.
This horse has three levels.
On the second level is a table and chair set that seats 4 on the top level is a set of chairs that seats 4.
You can sit on the horses head and stand on the deck.
You can't add furniture to this in the 2nd, 3 and 4 level...as it already comes with some. (unless you have a multilevel openspace and the skills so you can handle with it)
In the floor using shift +mouse to rise till the level of the floor of the trojan horse you can add furniture and looks fine :)