Pool table lights represent more than ambiance, they provide the illumination needed to play the game. The correct way to hang a light is a matter of opinion because every light hight is different so you will need to experiment on what height is best for your light. 

The main goal is to adequately light the entire surface of your table including the top of the rails and also allow enough room to shoot and maneuver under the light.

For 7 and 8-foot tables, hang a series of lights that equal 52 inches long combined. Nine-foot tables typically require a light that consists of one to four shades, totaling 62 inches long. Hang the lights 30 to 40 inches above the top of the table’s playing surface.

The pool table lights require shades that direct the light right to the table. Hang lights about 60 to 63 inches above the floor or roughly 30 to 36 inches above the felted slate surface of the pool table. An electrical light box installed in the ceiling allows you to hang the light above the pool table and plug in it.