The default field 'blank key' in a new table created with Microsoft Access can be changed later.
Open the table in Design View:
In Access, go to the "Tables" tab.
Double-click on the table to open it in Datasheet View.
Switch to "Design View" to modify the table structure.
Add a new field:
In Design View, you can add a new field by entering the field name in the "Field Name" column in the next available row.
Set the data type:
Choose an appropriate data type for the field (e.g., AutoNumber for an automatically incrementing key, or Text for a text-based key).
Set the primary key:
Click on the row selector box (the gray box to the left of the field name) for the field you want to set as the primary key. This will highlight the entire row.
Click on the "Primary Key" button in the toolbar.
Save the changes:
Save the changes to the table structure.
If you need to change the name of an existing field, you can simply edit the "Field Name" in Design View and then save the changes.
If there is a specific field named "blank key" that you are referring to, please provide more details, and I'll do my best to assist.