I believe there were only four 'Magic in Ithkar' volumes, which is a shame because Norton and Adams did a great job of soliciting (and editing?) these commonly-themed fantasy shorts.
Each of the four collections has the same prologue by Robert Adams, which explains how the fair originated in Ithkar (a religious anniversary turned pilgrimage), the set-up (temple, campgrounds for the merchants, docks and canals for the riparian traffic, etc.), and the difficulties encountered on a pilgrimage or trading voyage to Ithkar (Death Swamp, dragons, outlaw wizards). All weapons must be surrendered before entering the fair and wizards are discouraged from glamorizing shoddy goods with their spells. Of course, as at any large festival, the fair at Ithkar has its share of rogues, piratical merchants, bravos, potion-makers and witches, troupes of entertainers (not a few of them turning tricks), and gullible pilgrims.
A sampling of the fourteen stories in this volume:
"The Clockwork Woman" - Ann R. Brown
A mechanical doll is so deceptively life-like that when she is exhibited at the fair, a wealthy man in the audience tries to buy her. Unfortunately (or perhaps fortunately) for him, there's a real woman concealed within the doll. She is a dwarf and has fallen in love with her tall, beautiful mechanical persona. When she persuades her friend and fellow dwarf to take his place within a newly constructed mechanical man, she learns an important lesson in love.
"First Do No Harm" - Mildred Downey Broxon
Young Lithras is a character who could have been lifted from one of Norton's own fantasies--a young, untrained witch who is enslaved, then kills her master and escapes to the fair in Ithkar. She competes for a job as a body healer to a wealthy nobleman, and confesses to one of the other competitors: "I am no anointed healer, but a maimed thing, unfinished."--Doesn't that sound like a character from the pen of the Gandalf Grand Master of Fantasy herself? This story also has one of Norton's ambiguously romantic endings.
"Honeycomb" - Esther M. Friesner
Author Esther Friesner has also written and published many fantasy series, including the Twelve Kingdoms ("Mustapha and his Wise Dog"), New York ("New York by Knight"), and Tim Desmond ("Gnome Man's Land") novels. "Honeycomb" is one of the most magical stories to come out of Ithkar, and involves a mysterious candlemaker and her effect on a young woodcarver. A truly sweet, funny story in which an unfaithful lover is changed into a bear and a young not-so-maidenly maiden is forced by an enchanted candle to confess her urgent need for a husband.
If you are searching for good sword & sorcery short stories, you might find exactly what you crave at Ithkar's magical fair.