Please go to SE16N,
Give the table name T012K
In the transaction code bar enter '&SAP_EDIT' and press enter.
SAP editing function is activated.
now click on execute.
The table will open in EDIT mode. But, please make sure that you are editing / deleting the entries correctly.
This is not the recommended procedure to do. Therefore, please do not attempt to do in production.
Any wrong doing will have negative consequence.