Download and run the Autoruns utility from Microsoft's Sysinternals site.
https://learn.microsoft.com/en-us/sysinternals/downloads/autoruns
It's just a zip file and you can extract the executables to your favorite utilities folder. No install required.
In the search field enter "pdfeditor" like I did here with "oned".
Here I see that OneDrive is being launched from the "CurrentVersion\Run" registry key and the program is being launched with the "/background" command line parameter.
I don't know what "PDFEditor" is. Is that software that you installed, or did it come preinstalled on your Surface?
The main question is; what is it trying to do? The command line parameters may help you understand that.
If you decide that you don't want it to run, then you can uncheck the little blue check mark at the start of the entry. Autoruns will "hide" the entry.