Convert topojson to mapinfo tab

Download and install the latest version of Filestar.
Right click on one or more Topojson file(s) on your desktop and select Convert with Filestar.
Type convert to mapinfo tab in the search box.
Press Convert.

What is .topojson?

Name: TopoJSON
Extension: .topojson
Category: GIS
Developer: Mike Bostock
Description: TopoJSON is a file format for encoding geographic data structures, based on the GeoJSON format. It encodes geometries more efficiently and supports topology, which enables more accurate representations of geographic objects. TopoJSON eliminates redundancy and simplifies data, making it smaller and easier to work with.
MIME Type: application/vnd.geo+json
Wikipedia: .topojson on Wikipedia