No blank rows in the Field Name column

I am taking an ArcGIS class and we are working on creating a new parcel in a parcel fabric. I am simply trying to add a new attribute to the parcel fabric table. The instructions indicate to go to the Parcel Fabric Properties, click the Fabric Classes, choose the parcels feature class and then scroll down to the first blank field name to type the new attribute name.

Attachment 19492

The problem is that I do not have any blank rows? Am I missing something here? I do not see any method to create a blank row.

Thanks

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