To pass a TABLE-HANDLE by reference, use this syntax for the RUN statement in the calling routine:
( { [INPUT] | OUTPUT | INPUT-OUTPUT } TABLE-HANDLE tt-handle

    BY-REFERENCE).
If the called routine’s temp-table is a static temp-table, you can save the overhead of instantiating it by defining it as REFERENCE-ONLY:
DEFINE TEMP-TABLE temp-table-name REFERENCE-ONLY.