In each table in Raven's Google Analytics integration, you're able to change the Table Content and Dimensions at the top of the table, above the Display Settings and Table Settings icons. Both change the data displayed in your tables, but have different uses.
Table Content is otherwise known as Custom Reports in Google Analytics. This allows you to change the data set itself, switching from the default overview, to a particular goal set to ecommerce data and more. Changing the Table Content setting will change your metrics, giving you the data that is most appropriate for the table that you're looking at.
While metrics measure the data associated with your website traffic, Dimensions describe that data. Google defines a Dimension as follows:
A dimension is a descriptive attribute or characteristic of an object that can be given different values. For example, a geographic location could have dimensions called Latitude, Longitude, or City Name. Values for the City Name dimension could be San Francisco, Berlin, or Singapore.
Browser, Exit Page, Screens, and Session Duration are all examples of dimensions that appear by default in Google Analytics. Dimensions appear all of your reports, though you might see different ones depending on the specific report. Use them to help organize, segment, and analyze your data. In some reports, you can add and remove dimensions to see different aspects of your data.
In Raven, your default Dimension depends on the section you're viewing. For example, Social > Conversions defaults to Social Network. But, if you want to see conversion data for Ad Distribution Network, that data can quickly be changed by selecting the appropriate Dimensions from the listing.
Don't forget that Dimensions can be used in Custom Chart creation to make personalized reports based on the data you want most.