I had this very same problem, but I've made life easier for myself by using webmin to administrate my mysql tables.
If you are looking for the following scenario, this might be what you had in mind:
I needed to only grant access to a single db by a particular user. To do this, I set global user options to none, and database permissions to the one's I wanted. Then you have to remember to set the host permissions for that user. (localhost or other) That seems to be the only way to prevent users from seeing all the tables on the server.
If you want, I can send you a sample table structure query from the mysql command line.
email me at pr0ject at reject dot org.