A roll is a curled, thick, slow moving wax formation. It looks like a slowly rolling poster or piece of cloth and usually hands backwards off the side of the candle.
A wax roll on a candle is reasonably uncommon. These shapes occur to let us know that the energy of this work is wrapping around someone in a way that smothers them or diminishes their power and conforms them to the will of the spell.
Rolls are similar to nets in that both of them indicate that your target is going to be tangled up inside of the magic.
However rolls are considered to be much gentler and much more positive. They have an energy of gently but firmly persuading someone to come around to your point of view. Think of wrapping someone in a gigantic blanket and bear hug until they agreed to do what you want them to do.
What to Do:
Rolls are an almost universally positive sign. They indicate success in almost all types of work and at all locations on the plate. No need to do anything about them.