The applet begins with Random Shots turned on. So every 5-10 seconds the cue ball will shoot in a random direction. To turn this off, press the "Toggle Random Shots" button.

Gravity of 0.0 means no gravity. Gravity of 0.1 is Jupiter gravity. Gravity of 0.005 should work well.

The time between updates can be changed using the "Slower" and "Faster" buttons.

Use the left mouse button to shoot (press down where you want the end of the cue and then pull back, release the mouse button to shoot.) Use the middle mouse button to "grab" a ball and move it where you want it on the table.