I beg your pardon but I do not understand you. Whatever you would like to do to your 500 items list there's one way of doing things. Export bookmarks to bookmarks(.html). Then you'll be able to process your "items" in every way. Divide the list into two folders for example, or sort them etc. Import the file then back to Edge. MS Edge keeps bookmarks as json file without extension, but exports it to html file.
If you are able to open such big file with hyperlink addresses you may move your focus using Shift+click (cursor mouse). Shift+top area of the right slider will move you to the topmost position. Shift+click the bottom area of the slider column will change your focus to the bottom of your file. Shift+click in every other place (think of slider column as a sort of % ruler) will give you chance to quickly jump to any place within your list.
I used 4000 URLs one in Opera, but they were organized in folder trees and were easily to process. The same I am able to do in Edge. What's your problem then? -- MS Edge Dev 96.0.1028.0-1 Debian Bullseye GNU/Linux 5.10.46-5, X.org 1.20.11, IceWM 2.1.2 Nvidia GeForce GTX 650, Driver 460.91.03, systemd 247 (247.3-6)