Hi bjay,
Welcome to the cafe :)
A Reiki circle usually involves two or more practitioners giving you Reiki at the same time. This tends to make the amount of time that you are on the treatment couch shorter and the healing can be quite intense. I have found it can be very balancing to have two practitioners working on me at the same time. Sometimes healing circles include sending Reiki distantly too at the end. If there is anything you are unsure of at the circle, just ask, I'm sure someone will only be too happy to answer any questions you might have and allay any nerves :)
Hope this helps.
Gentle Blessings
Helen