On this page you can add a new field to the table. The editable parameters for the new field are :

Field name
  The name of this field in the table.

Type width (for varchar and char fields)
  The maximum number of characters allowed for data in this field.

Array field?
  If this option is set to Yes, the field will be able to store multiple values of the same type.

When done, click on the `Save` button to update the table structure with the new field.