Open multiple tabs in a browser, like Opera for example, and the System process, of all things, swells up like it caught a disease or something. This didn't happen in Windows 8.1.
Since Opera moved to Chromium (? - that Google Chromes' thing) I stopped using Opera. It does exactly what you showed, you open one tab in browser and in task manager it opens 1+ tasks... That Opera could be why you have so much consumption by System