Why did he tell them all this?
Vilna Gaon: When a person is in great Simchah and pleasures, and afterwards he sees pain, even a small pain, he can die from it. His cure is to blunt the pain from his heart, see (feel) honor and increase pleasures. Haman could have died from his pain, therefore he told them the honor of his wealth.
Malbim: Haman's grandeur dictated that he not notice whether or not someone lowly in Haman's eyes shows honor to him. His grandeur increase Mordechai's sin, but also prevented Haman from striking him, lest it lower his honor! Since his grandeur was the reason for his pain, he told it, to take counsel. His success was in three realms - multitude of acquisitions, sons and authority. Therefore, he boasted about these three.
How many sons did Haman have?
Torah Temimah citing Megilah 15b #1: He had 30. Ten died, 10 1 were hung, and 10 begged for bread.
Torah Temimah citing Megilah 15b #2: Seventy begged for bread. (Maharsha - he agrees that 10 died and 10 were hung.)
Torah Temimah citing Megilah 15b #3: In all, he had 208, like the Gematriya of "v'Rov" (it is written lacking a Vov).
Rashash (15b): This implies that the 10 that they hung were not the 10 killed (9:7-9), unlike Tosfos (Yuma 31a DH Amah). (If they did not hang the one killed, why did she request to hang only 10? Perhaps they were esteemed; she was happy to leave those begging for bread, which is a disgrace for Haman. - PF)
