It could be part of a Bar or Bat Mitzvah meal.
Most bar mitzvahs are celebrated at a Saturday morning synagogue service. After the service, there is frequently a kiddush luncheon -- that is, a luncheon that begins with the kiddush blessing over bread and wine. Later, that evening, it is common (but not universal) to have a bar mitzvah party starting with Havdalah, the blessing marking the end of the Sabbath day.
Luncheon is a noun.
"Teacher's Luncheon" means that only one teacher could attend. "Teachers' Luncheon" denotes the plural form, i.e. a luncheon for many teachers.
Kiddush (קידוש) means hallowing or sanctifying
When lunch is served to several people it can be called a luncheon.
It would be unwise to decline an invitation to attend a luncheon with the Queen. In America, plain old baloney is sometimes labelled as luncheon meat. Will you join me for a pleasant luncheon?
The plural form for the noun luncheon is luncheons.
A luncheon is just a fancy lunch, usually with guests.I can give you several sentences.The Ladies' Association held a luncheon at the church.I am going to the group luncheon because they are having a speaker talk about his travels to Egypt.Let's have a luncheon and charge a fee so we can raise money for the band!
Luncheon of the Boating Party was created in 1881.
I will be going to a business luncheon tomorrow with our new clients.
Luncheon on the Grass
If the luncheon is a special event such as a luncheon before a wedding then yes, bring a gift. If it is just an informal luncheon with either friends (no special reason) or business you do not need to bring a gift.