This option is controlled through Additional Elements in the Format (Table) menu.
Each option has an associated text box added to the table at an appropriate place.
Subtitle adds a text box below the Title.
Pagenote adds a text box at the bottom of the table.
Endnote adds a text box at the bottom of the table (after the pagenote if present).
Text is entered by double clicking in the associated text box. Uncheck the corresponding box in Format (Table) to remove the additional text lines.