I also have Sonar in English and Windows in French and this context menu also appears in French. I believe it's because this is a Windows menu and not a Sonar menu. Windows does not appear to have keyboard shortcuts for these controls (amazingly enough).
As for Sonar, here is what the arrow, page and home/end keys do (from Sonar help) :
LEFT/RIGHT ARROWMoves the highlight to the next or previous control. UP/DOWN ARROWMoves to the same control in the adjacent track, or the next track of the same type if the control only applies to a specific track type (for example, the Patch control only applies to MIDI tracks). PAGE DOWNDisplays the next page of tracks. PAGE UPDisplays the previous page of tracks. HOMEMoves the focus to the first track. ENDMoves the focus to the last track.So these keys are more track related than window related.