Can linked worksheets be saved to a flash disk

It depends on what software they're created in, how it manages links, and whether it allows for re-linking.

If filepaths (what are stored when a link is saved) are absolute then this will change the path of the file as it is saved to the drive. Obviously there is a difference between '/Users/joe/worksheet' and '/Volumes/USB\ Disk/worksheet' (I work on a Mac as you can tell from my directory format but the principle is universal).

If on the other hand paths are stored relatively, then /worksheet is the same no matter where you are and if both worksheets are in the same directory then it should work out fine.

I suspect most software uses absolute links to avoid any confusion, sadly. This is why I ask if it supports re-linking. The edit software we use here will ask for any linked files it can no longer find to be re-linked when it loads - this again depends on the software you are using.