As you are new, and not a mapmaker, I will just assume you haven't read all the other posts about this, so I will try to keep it short.
My map uses something called "preloading" That is, it loads all items, units, triggers, abilities, ect. into the game while it loads. This is to prevent lag spikes in gameplay. Though it doesn't effect lag spikes created by a poor internet connection.
Even the beloved DOTA uses preloading. However, CHA has ~2X as many triggers, 10X the number of units, and well.. I don't even want to get into items. Thus, the preload time is much longer!