These tools are intended to be used by WordPress developers for testing and debugging. The backup tool lets you do a quick backup of individual MySQL tables by duplication into the same database, i.e. using "CREATE TABLE copy LIKE orig; INSERT INTO copy SELECT * FROM orig;". Useful for testing when you know only some tables will be changed so you don’t have to save and restore the entire database. Most useful for repeated testing, i.e. backup table(s), test, restore table(s), test, restore table(s), … test, restore table(s), delete backup. The restore operation resets the contents of current tables to the contents of the backup tables but does not delete the backup tables so you can repeatedly restore a table. The backup tables will be named by concatenating the original table name with the backup suffix. It is important that no existing table have a name ending in this suffix. The backup tool can be accessed by clicking on the Dashboard menu item "Database Developer’s Tools".
Beware
If you have selected the wp_usermeta table do not log out without ending a database debugging session. Otherwise your session key will change and when you try and restore the tables the old session key will also be restored and invalidate your current session.
Version 2.2
The next version 2.2 coming in December 2016 will also optionally log SELECT operations which can be displayed by the "Diff Tool". A beta of version 2.2 can be downloaded now from GitHub.
WordPress Database Developer's Tools 