The ERA is organising Eddington Open Door (on the 7th) and Board Games (on the 13th) in December.
In addition, there are several Christmas-related events organised by other parties, such as the Knights Park Festive Market (on the 10th).
Check out the ERA events here: https://www.eddingtonra.org/events/calendar
and other events here: https://eddington-cambridge.co.uk/whats-on?eventm=12&eventy=2022