What is this usernoted process in my Macintosh?
That's actually not a lot of memory for usernoted, Finder, or Dock. "usernoted" is a known process and is installed with OS X. Do you mind telling how much memory you have, as well as what OS version? 
Also note that you clicked on the Compressed Memory column, rather than regular memory, which is a more accurate way of showing memory usage. Don't forget to show all processes (not just your processes).