We created a tool which helps you to remove useless post revisions from your database.
Whenever you or WordPress saves or drafts a post or a page in your WordPress, a revision of each edit is automatically stored in your database tables. Each revision will slowly increase the size of your database.
For example, if you have 1 post and it has 10 revisions you could be storing up to 10 copies of older and unused data in your database.
You can't delete these revisions manually, but, we created a plugin for this task.