A drinking session followed by a banquet is called?

There isn't a specific term for a drinking session followed by a banquet. It's usually described as:

* A pre-banquet drinks reception: This is a common way to describe a social gathering where guests enjoy drinks and hors d'oeuvres before a formal meal.

* A drinking session followed by a feast: This is a more casual way to describe the event.

* A celebration: This term can be used broadly for any event that involves drinking and dining.

Ultimately, the best way to describe the event depends on the specific context and the tone you want to convey.