Product and version (e.g. FileMaker Pro 14.0.3)
When you add fields to a layout, they're also added to the defaults for Table View. However when you also add fields only as merge fields within text, they're also included in Table view. This causes all sorts of issues in terms of how you style a merge field in table view, but also has issues for the DDR.
If you open the Table view "modify" options, you can turn off visibility on the layout. For normal fields, this shows up in the DDR as the tableViewVisibility flag in the FieldObj node as set to 1. ( 2 is on table only, 0 is both ).
However tableViewVisibility is only affected for Field objects and isn't part of the merge fields at all. So even if you switch them off on the layout, the DDR always show the text object as tableViewVisibility=0 as it can't distinguish between multiple fields within the same text block.
So there's missing data here in the DDR, but also a lack of visibility as to how to configure a style for a table view field that is part of a large merge text object.
How to replicate
Create a new file with two fields. Add them as merge fields to a text block and don't have them on the layout in any other form. Go into table view and turn one off. Generate the DDR.
Workaround (if any)
There isn't any.
I don't think merge fields should be part of Table View automatically. I think this is a bug. Mostly because you've no way of styling or formatting one field amongst many within a single large text block, to adjust how it displays in Table View.
There could be a simple workaround to have a per layout checkbox that allows merge fields in table view. But the DDR would need to be adjusted to include per field level info about visibility.