Hi, according to Apple's support document, Fn with up arrow scrolls up a page while Fn with down arrow scrolls down a page. However, it does not work when I try to do that under Edge in Windows 10.
FWIW, I'm running Windows 10 in a Parallels VM on a 2018 Mini with a non-touch Magic Keyboard with keypad. I can scroll up and down in Edge using the page up and page down keys as well as Fn with the up/down arrows.