While awful I would like for someone to explain what's in that 1.3GB.

In fact it's one of my major sources of unsatisfied curiousity is for someone to show a breakdown of a memory dump of a browser, to see, what happens to those gigabytes of memory consumed.

I have heard an explanation that browsers just use free ram, because unused ram is wasted, but that feels flimsy to me. It's not the browsers job to hog ram on the off chance it might need it, just ask the OS when you actually do.