Chris is headed in the right direction.Attic spaces are designed usually for storage and not habitable space.You also have to have the proper head height for habitable space(7').You may have to change the joist sizing up there before you do any remodeling.

First of all, i would ask other questions! Where is the home located, how many bedrooms, what will this do the my homes value, this question also should show what type of finished to use as well! Plus be careful this is may be a structual item as well! Pool table is quite heavy!