docs: def _idx_table_by_num(tables):
      """
      Switch tables to index-by-number
  
      :param dict tables: Metadata
      :return list _tables: Metadata
      """
      logger_jsons.info("enter idx_table_by_num")
      _tables = []
      for name, table in tables.items():
          try:
              # Get the modified table data
              tmp = _idx_col_by_num(table)
              # Append it to the growing calibrated age list of tables
              _tables.append(tmp)
          except Exception as e:
              logger_jsons.error("idx_table_by_num: {}".format(e))
      logger_jsons.info("exit idx_table_by_num")
      return _tables