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.
A Christian teacher I know characterized Beka, the publisher of this book, as being "obnoxiously Christian": the criticism is justified. The selections in this volume are strong until one gets to Trancendentalism ("the Recurring Failure") where the sanctimonious editorial voice becomes unbearable (did you know, for instance that, Whitman "could often write good poetry" when he could bring himself to "direct his mind toward good subjects"?). After this, the selections are bizarre: despite there being an entire Modern Poetry section, there is not a single poem by either Pound or Eliot, and not one single mention of WC Williams or Wallace Stevens.