As the meal comes to an end, finish all the food on your plate and get ready to sing, yes sing. You don't have to know the Latvian lyrics, but you are expected to partake in their traditions, one of which is to follow up a good authentic meal with a song.
If at a business dinner, don't discuss business. Meal time is meant to socialize and improve relations, not to close a deal or finalize details.
When eating at a sit down restaurant with a server, you should round up or tip about 10% of the bill. In bars a tip is appreciated but not necessary.
Drinks
Among the many local beverages, the most unique are birch juice and skabputra, which is a sour porridge beverage made from barley and milk. In addition to these, all common drinks like soft drinks, juices, coffee, and tea are available.
A fairly popular local alcoholic drink in Latvia is called maizes kvass, which is fermented from rye bread crusts. Beer is also popular, which can be served in various forms, some of which are made with honey. Imported beers, wines, and hard liquors are also widely available.
Generally speaking, the tap water is safe to drink in Latvia, but check with locals for any particular regional differences. Also, many people may have troubles adjusting to the local tap water, as it will most certainly be different from what your system is used to.