docs: def _place_tables_main(sheets, skeleton_paleo, skeleton_chron):
      """
      All the data has been parsed, skeletons have been created, now put the data into the skeletons.
      :param list sheets: All metadata needed to place sheet data into the LiPD structure
      :param list skeleton_paleo: The empty skeleton where we will place data
      :param list skeleton_chron: The empty skeleton where we will place data
      :return:
      """
      logger_excel.info("enter place_tables_main")
  
      for sheet in sheets:
          pc = sheet["paleo_chron"]
          if pc == "paleo":
              skeleton_paleo = _place_tables_section(skeleton_paleo, sheet, ["paleoMeasurementTable", "paleoModel"])
          elif pc == "chron":
              skeleton_chron = _place_tables_section(skeleton_chron, sheet, ["chronMeasurementTable", "chronModel"])
  
      # when returning, these should no longer be skeletons. They should be tables filled with data
      logger_excel.info("exit place_tables_main")
      return skeleton_paleo, skeleton_chron