Is is safe to import bookmarks from another browser into the Tor Browser? How can I import my bookmarks if it is safe?
I have not tried anything because I am not sure
The short answer is no, don't import preexisting bookmarks.
The long answer is it depends.
URLs (the web address data stored in browser 'bookmarks') are pretty flexible in their format and often contain embedded information of various sorts. While this additional data is typically appended to a URL (ie: any part of a URL that comes after a '?') there are many URLs that have identifying information included in the path or even the subdomain.
If you have any doubt that the URL that are you using is not a general address applicable for everyone, assume that there is identifying information embedded in it.