This report is a handy way to see what parts of your site or campaigns (i.e. tags) have performed the best, normalized for the number of URLs. For instance, let's say that you have 100 "blog" URLs and only 10 "news" URLs. Since more URLs typically means more traffic, it's hard to say if, pound-for-pound, blog is actually outperforming news.
This view corrects for that. It divides the tag by the number of URLs in it to normalize the performance on a per-URL basis. And it does this across filterable date range and media.
You can filter the report by
Tag(s)
Session media
Date range
And this report is generally good for answering the question "which groups of URLs perform the best in which channels?"