Davina - not the best of shots and not one of an empty dancefloor I'm afraid - just this brochure image. For most of the time the dancefloor was covered with carpeting as these images from 1987 show.
Dinner Dancing capability was introduced in 1987 after the re-engining in both Columbia and Mauretania Restaurants. Columbia received an octagonal wooden dance floor for musical entertainment and dinner dancing.