For one thing, the FAs used to come by and "set your table." That is, they would place a white tablecloth on your tray table and on top of that the salt and pepper shakers, butter and olive oil, bread plate and napkin/silverware. Courses were served directly on the tablecloth, ie, serving trays were not used.

By contrast, today a small tablecloth is placed on the tray table and the setup comes with the first courses - appetizer and soup - on a curved faux wood serving tray. Salad and main courses are served on the serving tray. The serving tray is removed and cheese/fruit and dessert courses are served on the tablecloth.

PS - I hate how some of the dishes spin around on the faux wood serving trays.