Is there a capability for managing plugin options?

The part of the capability is the job of the developers of the plugin. But normaly use the most plugins for manage options the object manage_options.

But if you will, that your editor only change the plugin options from one plugin, than is this not so easy. All options of the core check for this object and also the most plugins. But you can change the role for this object and hide the other plugin settings page and so on with the help if the plugin “Adminimize” for the role of your editor.

You can also change a rolle very easy via plugin “Members”.