Seeing as you can't actually download more RAM, to spare the life of your SSD, you can use AMD Radeon RAMdisk to share 4GB of RAM, for free, for:
- browser temporary files such as Chrome - instructions on setting it up here
- extracting ISOs, zips
- setting the default Download folder for your browser (if you don't want to keep the files)
- Spotify cache
I don't recommend setting it for Windows temporary files as they can grow beyond 4GB. There are more types of cache recorded in CCleaner or BleachBit but as they aren't updated often/are harder to change, I don't recommend going further.
Linux has an in-built optional RAM disk called /dev/shm, or shared memory. More detail and explanation can be found at Superuser.