Nah we are not off-topic, we simply suggested better alternatives than having a huge bloated hosts file. Especially on XP having such a large hosts file is a real killer of performance as the OP already found out on his own.
It can cause a slowdown, but stopping the "DNS Client" service and setting it to Manual fixed that problem (for me). I don't need that service, and most people don't.
As for going OT, I believe OP's original question was answered to his/her satisfaction. So what remains is to ramble on, chewing the fat so to speak.