This creates a site file (*.mds) that acts as a placeholder for all RDF triples on the HTML pages within the same folder and its subfolders. The site file can be opened like any other RDF data source, it can be imported into other data models, etc. When opened, it will scan the HTML files and always automatically stay up to date when the data on the HTML is changed.
You can see that TopBraid has built-in views to browse the class hierarchy, properties and instances. These are powerful mechanisms to navigate through the data space that is encoded in the HTML pages. In the example above, you can see that my current Microdata pages contain information about three Persons, as well as various address and location objects. The class tree shows the number of instances of each class. A double-click on an instance will display it on a form. You can see the form view of the resource http://knublauch.com (representing myself as a schema:Person) on the right. Here is a larger view, with the details of one of the children objects opened up:
At this stage, the circle is completed and are in HTML document where you can fix problems (e.g. a misspelled email address). Save the HTML file, and the RDF triple (on the form and elsewhere) will update automatically.