A menu, since there were different menus for different classes. While there are surviving menus for all classes, the third class menus are far fewer, since not very many of those passengers survived.

e: Take particular note of the addendum at the bottom of the third class menu. "Any complaint respecting the Food supplied, want of attention or incivility, should be at once reported to the Purser or Chief Steward. For purposes of identification, each Steward wears a numbered badge on the arm."

While we, looking at this third class menu, would consider it to be lacking, the food served to third class passengers on Titanic was the best third class service on any ship of the time, and White Star was srs bsns about the third class passengers being treated with the same civility as any other passenger.