If you come here, you drink beer. Don't be a pain in the [--] to the bar tender asking for tea and what sort of tea they have: it's the Beer Museum, come on!!!
Take few minutes to explore the menu, then you can chose to sample a few beers for about Czk 25-30 a 20cl glass (a bit pricey, considering in some places 0.5L of beer is 29 Czk but worth the experience).
Inside the place is long, the atmosphere is the one of a pub.