When you have created a template with tags you can check what information each tag contains by using the evaluate button. Just select the tag you wish to view its data and click evaluate. It will open a window containing all the data stored in that tag.
Imagine you have the table from Northwind data for Shippers:
This table contains a For Each tag and Out Tags. By evaluating the For Each Tag labeled <Shippers> you will see the list of Shippers with their Shipper ID, Company Name and Phone number will appear.
Select the tag you wish to evaluate:
Select Evaluate under the Blueprint tab:
This will prompt a window to appear. This window as shown below, contains all the information that is stored in that tag that will be placed into that tag when the template is outputted.