A tray liner is a piece of paper that’s placed between the tray and the foods you order. Here’s one from 1981, used by Mc Donald’s in the United States, from Jason Liebig’s stunning collection of McDonald’s items. The font in use is Eightball, a typeface without a credited designer, probably released in the early 1970s and available under different names at different manufacturers. This design uses the simpler alternates for a and g.
Some of the modern ones, if they didn’t come with my food on them, would make pretty good posters. They had all sorts of facts about some topic on them, such as the Olympics (when that is happening), with cartoon illustrations.