Your WordPress database (the MySQL database required of all WordPress sites) can become cluttered, unorganized, massive and cause your site to slow down or cease to display. Take corrective action!
WordPress automatically saves revisions of your posts and pages every time you make a change to same and save. This is a good thing, should you ever need to go back to an earlier version of your post or page to restore. (Your Internet connection craps out, the power goes out, etc.).
The “price” for this feature is unnecessary bloat to your database. I’ve seen sites with revisions to individual posts or pages numbering in the hundreds and over the course of years! Think about it, how many copies of your revised post or page do you really need? I’d say somewhere to none to nowhere more than your last one or two – at most!
Working on your MySQL database files is ill-advised for the uninitiated. A simpler and safer solution is to install and use the WordPress plugin: Optimize Database. Easy to use, safe, and yes, I do use this plugin myself!