Yes, you can auto delete the MassMailer Email Status/Activity History/Email Job Statistics values by setting the Scheduler from MassMailer Setup -> Utilities -> Schedule or Manual

You have an option to auto delete the records that are 30 days, 90 days, 180 days, 365 days older by a recurring scheduled job or one time.

You can also select what types of Email Events you would like to delete such as Open, Click, Bounced etc.,