Click the little down arrow to the left of the "Author:" field name when creating or editing the Info for conference paper (or any record type). You'll see that you can change "Author" to "Editor/Contributor/Translator/etc." Add Editors or other creators by clicking the '+' on the far right.
Yes, it's not immediately obvious as a UI feature, but it is a pretty good way of basically allowing an unlimited number of contributors of whatever type you like (2 translators, a few editors and an author or 12).
Add Editors or other creators by clicking the '+' on the far right.