SELECT Server DB Size


I'm trying to reduce the size of my SELECTServer database.  Currently its15GB which is unacceptable.  I've turned on the data retention and set if 6 months but this did not see much of reduction in size.  After closer inspection there are two tables which accountable for about 95% of space:



These contain data from the very beginning ~2015 and contains millions of rows. Is it safe to delete data form these tables?