Edge uses the Syncing features of W10. As long as your other PC W10 was using a Microsoft Login Account (not a Local Login), your new laptop is configured using the same Microsoft Login Account, all PCs using that Microsoft account will automatically get all 300 of your links saved on that other W10 PC!
Of course this requires that both the old PC and the new Laptop are running W10 Activated with legit licenses. I have like 8 W10 machines and the licensed ones all behave in this manner so I can guarantee it will work. On some of my test W10 machines, Edge also seems to pickup all my favorites from my original W10 machine, but several of those are not Activated so I can't guarantee it will work on your laptop that way
UNLESS it's W10 has been Activated with a legit W10 license. Even though, non Activated W10 machines seem to work Ok, you should know that.
Sorry, I can't give you a direct location, but I've never seen one that works, as the location for the links is shared across multiple dll libraries and lots of registry entries.
p.s. It took me many months of testing when W10 first came out to get my favorites to work on multiple machines, and I never did find a manual copy solution such as you are asking for. This solution works seamlessy, however, so you may consider at least trying it out as it will definitely solve your problem.
Hope this helps,
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