The field contains only null values. This field could likely be dropped from the data model with no loss of analysis.
Before removing the field, review and remove any uses of this field in Measures, Expressions or Variables. Failure to do so could introduce syntax errors in the application.
If you decide to remove the field, you should first identify and modify any references to this field.
1. Filter to the field in question. for example using the field name or "Filter Using this Flag".
2. Switch to other resource pages (Viz, Expressions, Variables, etc) that have a non-zero filtered count and examine how this field is used. Decide how you will deal with this field reference before removing the table. Should it be replaced by a different field? Remove the visualization? Or perhaps you will change your mind and keep the zero-row table for now.