I'm in need of some expert advice from people with more lore/roleplaying experience than myself. I'm currently finishing a house mod and most rooms for relaxing have some apples, strawberries, mead, beer and cheap wine in it. I would like to add some bottles of water or milk (with no or very small positive effects) to the drinking tables or some other non-alcoholic beverages. Useful, for example, when you're seriously roleplaying and have a hangover from the previous night.
But I don't see people drinking or selling non-alcoholic beverages. I know that in the dark ages people would sometimes prefer beer to water, because water was often contaminated.

So, what do you, roleplayers and lore experts think. Should I add water, milk, etc. to my custom house? Or is this not lore friendly?

Water is no problem as you can get it from every stream or body of water, and neither milk is a problem imho. Every bandit knows about cows so they must be somewhere. At least pregnant ones

And lets not forget one thing. It′s your game. If you want to add something and you think it′s appropriate, then do it.

One consideration with milk is preserving it. Fortunately, the magic of frost enchantments should provide no challenge here.

I would suggest you might consider pitchers for water however. I would be surprised if the folk of Nirn are gullible enough to embrace the idea of bottled water.

Milk drinkers typically were folks who owned a cow or goat, which they could get milk fresh from. I am not sure if there are any modding resources out there that to add either animals, but if there are you could put in a barn and some diary animals.