This free-to-enter monthly event is organised by CH Event and takes place in the Great Hall (and often some of the other function rooms) in the Priory Buildings of the Abbey.
Why not make a day of it and visit the Refectory cafe downstairs then pop across to the Hand-made, Second-hand and Vintage Sale just over the road in Trinity Church Hall from 2.00-4.00pm (entry 50p)...