I have this picture for my account
memory: quota: 220.4 KiB used: 207.5 KiB
I want to free the memory and sellram. Is it possible, and if yes, how to do that?
You can free up used RAM by deleting rows from contracts that you are storing data in.
You can also unset your account contract code if you have one set.
There is no simple way to purge all data you have stored in EOSIO. You will need to manually remove your data from the contacts you have used in the past. Parse your account history if you don't know what contracts are storing your data.
If you hold worthless and useless tokens (like some of the airdrops) or very small balances of a token for which you paid the RAM yourself, you can send the full amount to another account or token-contract to clear the RAM.
The typical implementation of a standard token-contract deletes the row and frees up the RAM if balance is zero.