Put in another vote for Vivaldi. It’s definitely lightweight. I’ve got an older server I keep around (for YAR HAR FIDDLE DEE-DEE purposes) and Vivaldi’s the Chromium-based browser that works best on it.

That said, the default browser I use on that thing is Waterfox Classic. Vivaldi’s lightweight, but it’s not as light as that.

Another note: a few years ago I would’ve actually been able to recommend Edge because to my surprise it actually worked pretty damn well, especially if you were trying to get sites to get Windows-oriented web-apps to function correctly on Linux. Unfortunately they’ve since pushed several changes that have made it truly obnoxious. Big fat memory hog that tries to load “recommended” content in the background and won’t stop sending to/receiving from sites even after you close the window/tab.