This is rare; it’s probably because you’re with a shared web hosting company that doesn’t allow scripts to run an optimize command via SQL statements (SQL “OPTIMIZE” instruction). Please consult your web hosting company on this matter.
WordPress creates transient options automatically; it’s difficult to stop it from doing so. The best way to override this is to clear the transient options on a scheduled basis. For example, WordPress may create 50 transient options in a week. If you schedule WP-Optimize to clear these options on a weekly basis, you’ll have far fewer building up.