Yes, it is possible and also as simple as you pointed it out, just by simply adding each style into your html file. But keep in mind, using more style sheets is not the best way in order to keep up a good performance.
While rendering your html, your browser is only able of downloading 2 parallel files at a time. So using more than 1 css file would have negative effects on your performance. To avoid that I would recommend using more css files during development and using some tools like Grunt or Gulp to put all of your different css files together into 1 file.
