blublublu
” I think Chaza”l had in mind…”
while it is nice to have your own pshat as to what chazal had in mind, the Rishonim offer theirs
Rashi says thisis a place where others dotn do that. Tosfos brings Rabbeinu chananel as it means he steals the food (less tha a perutah). and Rabbeinu Tam who says it means a full meakl (“pas”) which woudl make a restaruant worse than eating a snack in a supermarket.
Though according too all 3 of those Rishonim drinking from a water bottle (that is yours) where this is common practice, is allowed.