R’ Yehoshua Heschel of Buchav zt”l (Matzmiach Yeshuah) would say: “'ויאסף לבן את כל אנשי המקום ויעש משתה' - Lavan was a crooked person and was going to fool Yaakov into marrying Leah. In order to distract his attention and the attention of all the people of the city, he ‘wined and dined’ them so that they would all be busy with the beautiful party and not have any time to discuss the chosson and kallah. Later, when Yaakov married Rachel, this was no longer necessary, so Lavan saved his money and did not make any party at all.”
A Wise Man would say:
“If you kick a lion when it is down, G-d help you when it gets up.”