MapInfo Professional version 8 and above is able to import OS MasterMap data in GML format directly into TAB files, the main steps are summarised below:
The compressed .gz file supplied by Digimap needs to be uncompressed to .gml before importing the file in to MapInfo Professional. This can be done using a number of unzip utilities such as 7-zip.
Once unzipped, in MapInfo Professional select Table then Import to bring up the Import File dialog:
From the 'Files of type' drop down select 'OS MasterMap (*.gml)', as shown above.
Browse to the location of your unzipped your GML file and select the file and press Open.
In the GML Import dialog you are able to specify which layers you wish to import from the GML file using the drop down. If you are unsure, select 'All Layers'. Leave the 'Use GML Style' radio button selected as this will apply the styling specified in the GML file.
Choose a suitable directory to store the imported data:
Press OK to begin the conversion in to MapInfo Table (TAB) files.
MapInfo Table (TAB) files are the native format for MapInfo Professional. MapInfo Tables can be opened as a map in a new mapper window. Please see the viewing MapInfo Tables topic for further information if you are unfamiliar with this process.