A saying used to "tell someone off". The saying is commonly used in the place of "fuck off", or "screw off". The origins of this saying is unknown, but most associate "roll off" to be created by D. Ciot from Kitchener, Ontario, Canada
Person 1: dude, you got owned on your business powerpoint
Person 2: roll off man!
light bulb head that wears comdoms that roll off due to having a small willy