...
To import and overwrite an existing table, the sync capability controlled at the KB level through the power user interface must be used. This sync capability is different from the sync capability described for the admin console below.
Refer to Import Export for more information on KB-to-KB sync capabilities.
Permissions
This tab controls the table-wide and field level permissions for the imported table in the target KB. This is done by mapping groups in the source KB to groups in the destination KB, rather than setting permissions for fields directly.
...