As another datapoint, this HN page uses 56MB in Chrome for me.
But it has been a couple hours since your comment and the other replies :)
I don't know why they are different.
I get a 58kB HTML document, plus 2kB each CSS & JS, 3 * ~400B images, and a 7kB favicon.
Edit: Oh sorry, RAM. Leaving comment just to compare page size to RAM use for interest.
There's now ~388 comments. Source is 529kb and content 114kb (simple cut and paste of page, no markup).
Those are some impressive ratios.