The arrow on the file icon would indicate that it is an alias. You can also select that file, then Command-I (get info) on that file, which should also show that it is an alias.
Do you want to remove that alias file? Drag it to the trash.
(don't get too nervous about thinking that is your Applications. It's just an alias, a link, to the designated folder, and not the actual folder itself. If you want to remove the alias, just drag it to the trash - and empty the trash. It's gone.)
Why was that alias there in the first place? The "calibre-2.16.0" sounds like a download app. Many of those are the app, with maybe another file, in the same folder. One of those files will be labled "Applications", and is an alias like the one that you are asking about. That alias is simply used to install that app, as you drag the app to that alias, and it links to the folder (Applications, in this case), and by dragging the app to that alias, it automatically copies to the correct folder, Applications. Its only use is to install that app, after that you can remove it.
Deleting-removing the alias does NOT affect anything, except the alias file itself. 'tis just a link...