"Tea time" is something you especially travel to a fancy tea house to partake of and you must make reservations at the closest one to here as they are always full and otherwise nobody would ever get in. This family drinks herbal teas at home regularly out of teapots and all, but we don't call it anything special except "I am making a pot of tea, does anybody want some?" and it happens at any hour at all - just whenever someone feels the hankering for some tea.
Common phrase in the US - "brown bag it" is a colloquial phrase and equals bringing your own lunch, although it may or may not actually be in the brown paper bag (it may be in some fancy-schmancy city-chic lunch kit with matching containers and stuff). If the Europeans here don't know what a (brown) lunch bag is, it is a plain small brown paper bag that are just called and labelled "lunch bags" here in the US and come in packages of 50, and in one standard size. Those brown paper bags are permanent stock at all stores everywhere and are used for much more than just lunches - they are used for more crafts than you can count. All forms of "packing lunch" are used, too, like "packed lunch", "bring your own packed lunch", "don't forget to pack a lunch", etc.
Then there is the "after-school snack" for the school age set. And the "midnight snack" for those who like to raid the fridge in the middle of the night. Brunch happens sometimes (= BReakfast and lUNCH portmanteau, and replaces both meals - you wait a little longer for your breakfast and then skip lunch as the meal will be heartier than the typical breakfast here).
We have lots of other terms, but they are descriptive of what kind of food event is happening: tailgate party, picnic, barbecue, hog roast, cookout, wine tasting, less often "feast" (usually a religious term), sometimes a banquet, pizza party, cocktail party, weenie roast, crab boil... the list is looooong.
...and now I am hungry!