When I hear people say that, I just have a hard time believing them. Everyone I've met who said that and could show me, failed to demonstrate it in person. That doesn't mean you aren't doing it, maybe you are, but I'd be surprised and I want to know how.
Every single tab I open eats a ton, like 20, 50, 100MB or more at times. I don't see how you could have 100+ tabs open.
Its not just Windows either, I have the issue on Linux, Windows 7, and MacOS Snow Leopard and have for years. WIth and without any extensions loaded.
If you can do this, then there has to be some discoverable thing different in your setup verses others. Maybe we need to start a project where people save their tabs and share the file and we start doing some serious methodical testing to find out what is different among systems and setups that can or cannot handle it.