1.
banquet, formal dinner party, state dinner
A formal evening dinner event, typically hosted by governments, organizations, or dignitaries to honor guests or celebrate occasions. Often associated with diplomatic and state functions.
Usage
晩餐会 refers to a formal dinner event, typically in diplomatic, governmental, or high-society contexts. It is more formal than a simple 食事会 (dinner party) or 宴会 (banquet/party).
In Japanese news, 晩餐会 most often appears in reporting on state visits and diplomatic events, such as 宮中晩餐会 (an Imperial Palace banquet).