Diagnosis
TABLES parameters are table parameters. Table parameters are obsolete CHANGING parameters that are typed as internal standard tables with a header line. If an internal table without a header line or a table body is passed as an actual parameter to such a formal parameter, an empty header line is generated in the function module. If an internal table with a header line is used as an actual parameter, both the table body and the header line are passed to the function module. In the case of formal parameters defined with TABLES, no value transmission is possible.
Formal parameters defined with TABLES can be replaced by formal parameters defined with CHANGING. A local work area can be created in the function module for the internal table using the addition LIKE LINE OF itab of the DATA statement in the function module.
solutions:
create an table type in se11 and set it in se37->Changing