Hello ellaryk,
Nearby Sharing lets you instantly share your videos, photos, documents, and websites with people and devices near you over Bluetooth (4.0 or later) or Wi-Fi, but not over Ethernet.
https://www.tenforums.com/tutorials/97582-turn-off-nearby-sharing-windows-10-a.html
If you like, you could share files and folders over a network using the method in the tutorial below instead for Ethernet.
https://www.tenforums.com/tutorials/111783-share-files-folders-over-network-windows-10-a.html