Why there is no se’udah on Chanukah
We have a se’udah (festive meal) on Purim, so why not do likewise on Chanukah?
In his glosses on the Shulchan Aruch, Moses Isserles (the Rema) quotes a certain Rabbi Avraham of Prague who says there is a sort of mitzvah but not an obligation to have a banquet on Chanukah.
Rav Joseph B Soloveitchik cites a Midrash on Parashat B’ha’alot’cha that says that God’s original plan was to have the dedication of the altar (in the time of Moses) in the Tabernacle on 25 Kislev but circumstances made it necessary to move it to Rosh Chodesh Nisan.
The month of Kislev objected strongly to the change, and God consoled the month by saying that in time to come the altar would be rededicated on 25 Kislev, the original date.
However, though there would be a happy atmosphere and fasting and eulogies would be forbidden, it would be up to the people of Israel to decide what character to give to the day, including whether to have a full banquet.