Green’s Dictionary of Slang

eat-up n.

(Aus.) a meal; thus eat-up joint, a restaurant.

[Aus]W.H. Downing Digger Dialects.
[Aus](con. WWI) A.G. Pretty Gloss. of Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: eat-up. A meal.
[Aus]T. Ronan Only a Short Walk 4: The eat-up joint three doors down the alley.