Two main cases
- If these tables are standard tables, you must use BAPI, CALL TRANSACTION (or BTC) or any valid access given by SAP
- If these tables are customer tables, you may use the DELETE statement, but insure yourself the coherence of the database (don't delete an header leaving poor orphan items behind...) look for foreign key in where-used.
Also this question has already been answered many times, perform some search at sdn.
You can create a normal ABAP report to delete or modify records from database table.
You can use statements such as delete or modify for this purpose.
First select the records from table bring them into internal table and use that table to delete the records from database.
Note: If you are trying to delete records from Z tables then this approch can be adopted but if you are dealing with Standard tables it`s not a option to directly delte the reocrds from database table .
For that purpose you can use BDC or any othe available FM/BAPI.
Note :When you are deleting records from the database table please use locking function module to lock the database entries.