The Editor File could contain the following:
The Current VOICE as well as the Banks USER 1, 2, 3, 4, (4x128 = 512); the current Song or Pattern's "Mixing Voices" (16) and/or USER DRUM bank (32).
The Current SONG/PATTERN MIXING setup (all parameters).
Your selected Favorite (Presets)
Your global (Utility) settings

The idea is the Editor has three modes: Voice, Song, Pattern.

(It does not include any Performance or Master mode Programs; nor does it include any audio sample data). It takes inventory of the items you mark on the BULK > DATA SYNC page. It is a Voice librarian that can contain (at maximum) the current User inventory of Voices plus the current Mix. It is a snapshot of your MIXING setup which can include the 16 Voices you've placed in the 16 Parts, and the MIXING Voice, if you have created one for a PART, plus it includes every potential Voice currently in your XF's internal memory (these could potentially be used in a composition via Program Change).

Go to BULK > Data Sync:

The Song/Pattern Mixing setup is typically used when working with a computer DAW. While the DAW records MIDI Events and perhaps audio, you can also have the Editor File memorize the "current" (1) multi-timbral MIXING program plus all the User Voices you might possibly use via Program Changes... Typically DAWs do not store anything beyond the current 16 Voice locations (if you use the Midi Device Manager's XML script File). The EDITOR contents is automatically bundled with your DAW file (if your DAW is VST3 compatible)... this way you have both the sequence and the synth tone generator data bundled in your DAW File.

When you load a Cubase .CPR file, for example, this information is stored with the Cubase Project file, so that every setting (and the entire internal inventory of Voices) is set to be restored to your Motif XF (external) hardware. The Editor works via MIDI Bulk data, and can act as an external reserve - you can when OFFLINE access your entire VOICE inventory (if you have transferred same to Cubase's MediaBay). With its advanced search capabilities you can recall any VOICE and restore it to your hardware XF by simply bringing the Editor ONLINE - making it an elegant way to AUDITION sounds.

For example, if you are looking for an appropriate Electric Piano sound, you could load the 512 USER1-4 locations of your XF with Electric Pianos and then audition them one at a time. But say you have over 1600 Electric Piano sounds... the Editor allows you to access the 1600 Voices from one place (your MediaBay>SoundBrowser). As you click on a Voice in the Sound Browser its data is "bulked" to the XF's Edit Buffer - where you can quickly audition it.... Discard it and select another or you can store it to your internal XF.

Hope that helps.