Each Data Sync profile extracts a different set of information from the database, depending on the template passed to it.
If you want your tables to be included in the Data Sync export for a profile, you must extend the correct template. Place the extended templates in the install_dir/extensions/global/template/resource directory.
The templates associated with the profiles are similar to the API templates (refer to About extending API templates), but with only the entity names and no attributes.