Do you have any nodes installed that try to communicate with devices on the local network?
All of those IP addresses, as @afelix says, are typically local network addresses rather than public addresses on the internet.
It looks very much like something is searching random IP addresses for things on your network. That could be 'normal' if its a node looking for devices of a particular type for it to control, but it could also be something bad trying to find vulnerabilities in your local network.
You say you have removed all your flows. Have you checked you have removed all configuration nodes as well? You can check by opening the configuration node sidebar panel in the editor.
You could also delete your flows file, or rename it so you don't lose it, and start with a completely blank workspace.
