I don't mean the following in any way disrespectful or condescending.
The real question should be, which ones are safe to delete? It would be impossible to tell.
Make sure you have a valid backup image of your drive and whatever else it takes to recover your drive if something goes wrong. Test the backup and recovery media.
After doing this, delete to your heart's content. If something goes wrong, you'll at least have an option for recovery.
Everything I see with a few minutes of researching says it's completely normal to have multiple ntuser.dat files and it should not be deleted. The files do not take up much space, they do not hinder performance.
Why you have 140+ is as much a mystery to me as it is the internet as I'm not finding much on a PC with that many.
You can use
Treesize to see the space they use. Under the scan tab, search tree, type in ntuser.dat. It will display all the files with the sizes beside each.
