DFeast: Xerxes feast leads to drunkenness & a desire to show off/flaunt his wife's beauty. He is angry when Vashti refuses & their marriage breaks down. (1:3-22)
Some feasts are a bad idea and often when the ingredients of males, alcohol & party come together women become the topic & desire. When boasting of our wife's beauty we ought not say anything that could shame or embarrass them. And certainly we should not call them into the midst of the party with the intention of showing them off the way Xerxes did. When feasting we ought to remain sober minded as 1 Peter 5:8 reminds us, and careful not to get carried away in the moment.
CFeast: Esther's feast was thrown by Xerxes in celebration of his beautiful new bride. (2:18)
Marriage is a time for celebration. While it is undoubtedly a time when a groom shows off the beauty of his bride, it is to her glory and is far removed from the motives of Xerxes' previous feast.
CFeast: Esther invited Haman & Xerxes to a 2 day feast in order to talk with Xerxes about Haman's plan. (5:5&8)
Often we need to discuss sensitive matters with others, and sharing a meal can be a great place for this communication. The first feast wins her husband over (5:6) and at the second she can freely reveal her request. Perhaps we need not rush things, but use meals to deepen relationships and friendship so that the difficult things can later be discussed.
CFeast: We see the Jews holding a feast in joy over their salvation. Rather than the 1st feast in this book which sees separation, this final feast actually sees many non Jews beginning to claim to be part of God's people. (8:17)
The Christian Church has reason to be glad & to rejoice over an even greater salvation. Gathering at the Lord's table & sharing meals together (perhaps not necessarily separate events) are great times to delight in our redemption, in fellowship and community with God's people. And who knows, some who are outside of Christ may hear of Jesus' saving work for us and begin to fear Him.