At the top of the list is the default applet as macOS starts when you double-click files that share the same suffix or extension, with other programs associated with the file type beneath it, and one Other. option at the bottom that lets you choose an alternate app if the one you want is not listed.
You can easily change the default app associated with a particular file to something else. To do that, click Get info in the context menu and select another app from the drop-down list Open with: in the file's information panel. To use that app to open all the files that share the same extension, click Change All … button and select Continue .
Clearing it open with the menu
If you have installed many applications on your Mac over the years, you may notice that some apps appear in the Open menu that really does not have anything to be there, given that kind of file you have chosen.
In addition to unrelated apps, you can even see references to "ghost apps" that you removed from your Mac long ago. All of this results in a long and messy list of launch service connections you do not want to use.
Unfortunately, the list is not directly editable, but there are a few ways you can clear the crude from. An alternative is to take Titanium Software's free Onyx system utilities and perform a task to rebuild the Launch Services database.
Alternatively, if you're comfortable with a command prompt, open a Terminal window and run the following command, which does the same:
LaunchServices.framework / Support / lsregister -kill -r -domain local domain system -domain user
Run the command for a few minutes while the LaunchServices database is rebuilt and when the query appears again, enter killall Finder and press Enter to see the changes in effect.