When viewing records in the backend, you can choose which fields in that record is visible. A normal list view of a page:
If you click on the header of the record type, in this case 'Page content', it allows you to view records of just that type.
If there are lots of records, Typo3 will only display a few of them. Clicking the record type name lets you go through the pages by pagination. It also allows you to customize how the records are listed.
You can see here that I have chosen 'Date' and 'Subheader', which now show up at the end of the record. If a CSV export is done, these fields will be included in the output.
Hold down shift to choose multiple fields, and click 'Set fields' to make the change.