In searching this title, it seems there could be very many different things.  There are some poems, books, and compilations all surrounding the story of King Arthur and the Round Table.  I may have spelled it wrong, but the only book I can find is Le Morte d' Arthur, which are supposedly romantic tales of King Arthur, Guinevere and Sir Lancelot compiled by Sir Thomas Malory; first published in 1485.  I am going with this, as it does seem likely to be something Elsie would have liked to read.