Topics can be imported into the CMS using the import templates found in each content section (Sessions, Speakers, Exhibitors, etc.). In the template, there will be a column labeled "Topics". In the Topics field, list the topics associated with each item, comma-separated. Apostrophes cannot be included in this field.
Once uploaded, your items will be tagged with the Topics in the CMS.
Learn about Topic Tagging Best Practices here.