The book is available at Internet Archive, Hathi Trust, and Google Books.
Helga
Thorstein
I How Thorstein Lost His Kingdom
II His Arrival at the Giant's Castle
III The Mystery of the Locked Room
IV How Thorstein's Kind Actions Received Their Reward
Sigurd
I Sigurd Finds a Friend in His Stepmother
II He Wrestles With the Giant Sisters
III His Meeting With Helga
IV His Escape on the Wonderful Horse Gullfaxi
Lineik and Laufey
The Five Brothers
Hermod and Hadvor
Ingebjorg
Hans
I Hans Starts on His Travels
II His Wonderful Adventures and How He Returned Good for Evil
The Giantess and the Granite Boat
Greybeard
I The Strange Adventures of Geir
II How Greybeard Outwitted the King and Won Princess Sigrid
Litill, Tritill, The Birds and The Peasant Lad
Laughing Ingibjorg
I Thorwald and Ingibjorg Are Cruelly Treated by Their Stepmother Who Tries to Get Rid of Them
II How Thorwald and Ingibjorg Found Themselves at the Witch's Island and What They Did
III Their Further Adventures and Escape
IV The King's Return and Queen Guda's Release From the Witch's Thrall
The Three Peasant Maidens
I How Queen Hertha Fell From Her High Estate
II What Had Befallen the Two Little Princes and Their Sister
III Olga's Courage Rescues Her Brothers, Queen Hertha Is Restored to Her Husband, and the Parents Recover Their Children
The Fair and the Dark Isolde
I Death of the Queen. The King Remarries and Proceeds on a Tour Through His Kingdom
II What Befalls Fair Isolde After Her Father Has Gone
III Fair Isolde Escapes and Disguises Herself
IV Fertram Falls Under a Spell and Is Betrothed to Dark Isolde
V The Spell Is Broken and the Wicked Queen's Designs Are Frustrated
Prince Hlini
Fertram and Hildur