After deleting a Reference, the selection moves to the top of the database.
If you are going through the database and tidying up references deleting one at a time, it's disruptive for the selection to move to the top of the database.
A better behaviour, in my opinion, would be to highlight the previous or the next reference.
Adding a comment to bring this request into attention again.
Recently I was just at the scenario described, trying to remove some references from a really big bibtex file; it was really annoying that I had to find my way again through the file after deleting some entry.