A high ratio is a sign that your site captures your visitors interest since a visitor who spends more time on your site and goes deeper inside will generate more page views than an visitor who just glanced at the home page and left. In that respect, this report is the opposite of the bounce rate report.
Note that there is no 'right' value for the page views per visitor ratio. It's used to compare traffic patterns over time on a given site. For instance, if you redesign your navigation and the page views per visitor ratio suddenly drops, then it is a sign that your visitors may be confused and unable to navigate the new site. Seeing that report drop is an alarm bell telling you that something is wrong.