I honestly wouldn't even worry about it. You aren't hitting your 8GBs that you have installed and even then, Mavericks will resort to compression before it starts paging. Seeing as how your compression and page usage are 0, I wouldn't worry.
As for Spotify, is it even open? A lot of times it will run in the background and use up unnecessary CPU and RAM resources (albeit rather small %). It's located under Spotify Preferences -> Allow Spotify to be opened from the web.