The reference to everyday objects taking on malicious tendencies on Doctor Who refers to two serials, Spearhead from Space and Terror of the Autons, which debuted in 1970 and 1971 respectively, and starred Jon Pertwee, the successor to Patrick Troughton. Terror of the Autons featured a plastic beanbag chair which collapsed in on the victim and suffocated them, and is probably what you are thinking of. There is no case that I'm aware of, of a Doctor Who episode featuring a piece of ordinary luggage eating its victim.
Hope this helps!
Added referance to the Luggage's 'children'
In Interesting Times the Luggage went off with a apparently female Luggage and was later seen with several smaller Luggages. OK this is kinda different as it involved cutting down trees but under the circumstances I think this could be considered reproduction of a sort.Lucek 07:10, 27 August 2011 (CEST)