Various is the correct author for any book with multiple unknown authors, and is acceptable for books with multiple known authors, especially if not all are known or the list is very long (over 50).
If an editor is known, however, Various is not necessary. List the name of the editor as the primary author (with role "editor"). Contributing authors' names follow it.
Note: WorldCat is an excellent resource for finding author information and contents of anthologies.
Nice collection of crime and suspense by op Suspense authors, a group joined together to present e-books of some of their best work.
Stories are:
1: Unreasonable Doubt - Max Allan Collins
2: Death's Brother - Bill Crider
3: Poisoned - Stephen Gallagher
4: Remaindered - Lee Goldberg
5: Fire In The Sky - Joel Goldman
6: The Baby Store - Ed Gorman
7: The Jade elephant - Libby Fischer Hellmann
8: The Big O - Vicki Hendricks
9: The Chirashi Covenant - Naomi Hirahara
10: El Valiente en el Infierno - Paul Levine
11: A Handful of Dust - Harry Shannon
12: The Canary - Dave Zeltserman
13: The Chase - Top Suspense Group
That last is a round robin short story where each author wrote 250 words, then passed it to the next. That one would take off from there and send it on. It passed through every hand twice before the tale reached a satisfactory conclusion.
Available as as e-book from Kindle/Amazon. Worth a look .