We prohibit your bringing in items from outside of stores, especially not those of drinks and something to eat.
( we often use here is our department, shopping stores and mall's line stores in japan.)
Here is my side story about your suggestive expression from our japanese view.
We're proverbly well known this type ' firm' express. in japanese common usage and saw often around.
just above and your notifying note both also frequently and especially saw in Japanese shopping mall or department stores' cafe and stores recently. We're commonly forbitten to take into our own food and drinks-
i mean that are bought outside of the shop you want to enter. so, this notice says that stopping your bringing in the shop from outside to eat and drink and items not-buying there and near around.
there often you see places to buy things likewise. mostly where you can go and buy to get anything you eat and drink. you eat and dink in dued places and purchasing items displayed around near, to consuming contributing that shop and shopping mall, department store, that belongs to that shop, for sake eithier.
maybe our ritual is a little bit different from yours.
I'm appreciated if my writing in is rather helpful for your sake, than i excet it.