There is a database in phpmyadmin called phpmyadmin
At least there is in my version, and it includes a table called pma_bookmark
However, out of the 7 tables the database contains, there is only one row of data and that is in the pma_bookmark table
I think it's something phpmyadmin uses and is not for general use
Edit:
I've just worked out that the row contains a query I saved when fixing tables in one of my databased from within phpmyadmin so I wouldn't have to type it in again in future.