I think we need to make a separate page as well to manage the central columns list. Where user will be able to view the complete list of columns and add/remove/edit some if needed. I have few question regarding the same:

1. Do We really need a separate page ? or add/remove options on db_structure and tbl_structure page is sufficient? but no edit option we'll have in this case.

2. How the page should look ? Similar to tbl_structure page with option to edit and remove a column from the list ? but this can be very long as one database in total may have lots many columns. introduce pagination ?

Please share if any other idea ?

Thanks and Regards

- Smita