[Xenophon]

As best I can tell, for single-line and single-field entries, they like the 'and' or '&' separator between authors. You can probably also get away with a ',' but then you must beware of individuals with names like:
Ivan IV "The Terrible", Tsar of Russia
or
Tsar Ivan IV "The Terrible", of Russia
either of which could show up in a plain old author field. Basically, you may have commas and periods within the names of authors and editors. They seem to have settled on expanding multiple family members into separate listings, though, so my copy of "Tales from Shakespeare" whose title page says "by Charles & Mary Lamb" would be catalogued with authors "Charles Lamb & Mary Lamb."

It is interesting to note that the whole thing is ambiguous -- even using & or and as a separator, you can still run into either of those as a part of a name. Consider corporate publications as a possible example.

After kicking it around for a bit and reading through the various resources she pointed me at, I'd recommend just separating individual authors (and editors/illustrators/etc.) with '&' in both fields.

Xenophon

P.S.: Your example above would thus look like:

Fyodor Dostoevsky & Richard Pevear (translator)

and in author sort

Dostoevsy, Fyodor & Pevear, Richard, (translator)