Existing RFC to load table data, and to get list of tables and list of BAPI's in SAP

I am not sure that there exists a BAPI to see list of all BAPI's in SAP system. You can use the Function module RFC_FUNCTION_SEARCH to search for function modules starting with BAPI*.

Getting List of BAPIs

You can call Function Module BAPI_MONITOR_GETLIST to get list of all available BAPI's. This function module provides comprehensive information about Business Application Programming Interfaces available in your SAP system ?

CALL FUNCTION 'BAPI_MONITOR_GETLIST'
  EXPORTING
    OBJECTTYPE = p_ojtpe
    SHOW_RELEASE = p_rel
    BAPIS_POTENTIAL = p_poten
    BAPIS_NEW = p_new_pabi
    BAPIS_OLD = p_old_bapi
    RELEASED_BAPI = p_rel_bapi
    RELEASED_FUNC = p_released_func
  IMPORTING
    RETURN = d_ret
  TABLES
    COMPONENTS2SELECT = int_cs
    SYSTEMS2SELECT = int_sss
    BAPILIST = int_bapilist.

Reading Table Data Using RFC

There exists a Function module RFC_READ_TABLE, which can be used for external access to SAP R/3 system via RFC. This powerful function module allows you to read data from any SAP table remotely.

Getting List of Tables

Using RFC_READ_TABLE, you can read table DD02L to get the list of tables in the system. The DD02L table contains metadata about all tables in the SAP system ?

CALL FUNCTION 'RFC_READ_TABLE'
  EXPORTING
    QUERY_TABLE = 'DD02L'
    DELIMITER = '|'
  TABLES
    OPTIONS = lt_options
    FIELDS = lt_fields
    DATA = lt_data.

Conclusion

These RFC function modules provide essential capabilities for external systems to interact with SAP data and metadata. RFC_READ_TABLE enables table data access, while BAPI_MONITOR_GETLIST helps discover available BAPIs for business operations.