What are the names on the wall in the Crew Deck?

Yes, this is a memorial plaque to the crew members who have been lost.

If you're particularly careless/heartless, the list can get pretty full, apparently (as LessPop_MoreFizz linked in chat):

Many names on this list coincide to fallen soldiers whose dog tags you picked up during the Mass Effect 2 Normandy SR-1 crash site assignment.