Unmount any .dmg volumes you have open, on the left side of a Finder window, by clicking the Eject button when you scroll down on the left side of the Finder window to where it says Devices. You might have a .dmg volume open with a copy of a VLC Media Player .app bundle on it. I have had that happen to me in the past and cause this to happen.
Also, you might have an .app bundle of VLC Media Player that is an older version in your Trash, and you can still run an app that is in your Trash until the Trash is emptied. So try emptying the Trash for macOS. I have also encountered this occurring with deleted apps if I have not emptied the Trash.
If you still have multiple entries under Open With there is a good chance you have multiple .app bundles of VLC Media Player installed. There is the /Applications folder that is system-wide and the ~/Applications folder for the current user. However you can actually have an application in any folder at all on your disk, for instance I have a few applications that are in subdirectories of ~/Documents and ~/Downloads and they show up in the Open With lists for the types of files they can open. If you have an .app anywhere on your disk and have run it before macOS will probably know about it and list it in that menu.
Only apps that are in one of the 2 Applications folders will show up in Launchpad (that full-screen thing that shows you all of your apps and lets you click on one to run it and has a diagonal rocket ship for an icon), but an app from anywhere on your computer can show up in Open With lists, or be linked to from your Dock for that matter.
And actually an .app bundle is a directory rather than a file and macOS just gives you the illusion that it is a file, but that is another story. The point is, if you have an .app anywhere on your hard disk it is likely to show up on Open With, or if the .app is on any mounted drive such as a mounted .dmg image, or even if the .app is in the Trash. To make an .app disappear from an Open With list you need to delete it and empty the Trash and unmount any disk image it might appear on.
The directions Felix Paul Kühne linked to above are for cases where, even after doing all of that, the .app STILL shows up in the Open With list. But you need to GET RID of the .app FIRST, before doing that thing about rebuilding the Launch Services database.
If you want to keep a copy of an .app you are deleting, you can keep it inside a compressed .zip or .dmg file that is NOT mounted, to avoid completely deleting it in case you want to restore it later. I use the free, open-source archiver
Keka for this purpose (open source under GNU GPL version 3.0). Free open-source software is much less hassle than proprietary software, no need to buy or activate it or any of that nonsense.