A Jedi Super Slam is performed by tapping A twice to double-jump, followed by the X button to attack while in the air. Any character with a lightsaber can perform this move, driving it straight down and damaging any enemies in the immediate vicinity below you.
In Episode I, Chapter 6 "Darth Maul", there is a phase in which two battle droid commanders, located on platforms on either side of the arena, summon in about ten droids each. Allow them to gather in a pack and double-jump over them so that you can Jedi Super Slam into the pack. You should easily be able to destroy five of them in one attack.