Currently, when you search in Google and the knowledge graph comes up, it shows you up to five related people, books, albums, movies and so on. If you want more, you are out of luck. But with this test, Google is adding an “explore more” more link that gives you a lot more related topics to scroll through right at the top of the page.
Here is a picture:
As you can see, you can use the arrows on each side to scroll through more related people or topics.
I personally do not see this feature being tested and I’ve asked Google for a comment on this test.
Postscript: A Google spokesperson confirmed this as a test telling us “Google is always experimenting with new features to improve the search experience.”