Yes, essentially. But it is meditation with a purpose.

As with all things in The Master Key System, it is ideal if you can understand the exercise within the context of the entire text of the chapter, and not just one paragraph.

The preamble of the chapter says this:

The keener the sensibilities, the more acute the judgment, the more delicate the taste, the more refined the moral feelings, the more subtle the intelligence, the loftier the aspiration -- the purer and more intense are the gratifications which existence yields. Hence it is that the study of the best that has been thought in the world gives supreme pleasure.

Most people (including myself) accomplish our thinking process by chaining together an almost constant stream of random thoughts. Some of these thoughts we are scarcely aware of. How valuable are these thoughts, really?

The exercise is meant to help you achieve mental mastery. The purpose of the exercise is to show you how to take control of that stream of thought. By quieting the mind, we learn the ability to replace the random stream of thoughts with new, carefully chosen, more powerful thoughts.