I have a kind of the same problem. I use Evernote for over 5 years now. I always use a MacBook Pro. On the moment a MacBook Pro 2017 - OS Mojave. HD is 1 Tb. Still I'm struggling with a fast growing amount of data. So looking for where it is growing so fast, I found my Evernote local database is growing to 44 Gb.
When I had a look inside I found a lot of big files (10 -25 Mb). I checked a day with a lot of files. Much more than I normally add. One clipped webpage and about 20 additional pictures on a higher resolution (1.9 Mb) became 58 folders in the database and about 73 Mb. Older notes are in general 1-1.5 Mb each. So it seems that when I clip the note and then add the additional pictures. I merge them to one file and do some editing. But this creates a huge amount of copies. According to the database, this is happening since march 2018.
Is there any way to make the database smaller again?