this article says it comes from Europe, Great Britain, etc.
http://www.foodwoolf.com/2010/08/history-of-tipping.html
Yes. If you read either historical novels (current novels set in the past) or historical novels (novels written in the past), you will learn that giving a tip or “vail” to service employees other than your own was expected.
This makes “vail” part of a triple homophone, vail/vale/veil.
In France, the tip is usually included in your bill. Anything additional you my wish to leave is a plus, but the server is guaranteed a “tip” because it is included in the price...as is any tax. It is why in America servers are often “stiffed” because visiting Europeans do not have the habit of “tipping.” They assume the service is included in the bill.