Is it possible to delete an unnecessary object that was created in the editor's catalog?

Hello. I have a question: can I delete an unwanted object I created in the editor catalog?

You can hide it from the panel — take a look at the NCF; there are pre-created catalog entries for all units there, but they're not visible.
This is controlled by the line <HideInEditor>false</HideInEditor> — change it to true