This apparently is related to Adobe Creative Cloud, and appears to be used to house log files for Adobe CC. It is *not* the same Library folders that macOS uses to store your settings, etc. - which are located in an entirely different location on the hard drive.
See this post on StackExchange:
https://apple.stackexchange.com/questions/414851/a-library-folder-appeared-in-my-documents-folder-on-mac-is-that-normal
I had the same Library folder, and I also until a week or so ago had Adobe Creative Cloud installed on my machine.
I was not able to browse inside the folder, but I was able to successfully both move it to the Trash, and empty the Trash.
If you plan to keep Adobe Creative Cloud, I suggest to check with Adobe about the consequences of deleting that folder before you do so.