The DataSet window displays the values matched by the extractor tokens. It can be view in two basic ways:
The DataSet window has two rendering styles. The default is grid view, but you can switch between views using the button at the top of the screen (after view as:).
The names of the columns correspond to the tokens that matched data in the most recent scrapeable file's response. The one addition is the Sequence column that is used by screen-scraper to identify the order in which the matches occurred on the page.
If a column is not showing up for an extractor token it is because that token does not match anything in any of the data records.
This view can be a little easier for viewing the matched data in data record groups.