Luke,
The extreme width of these corridors was only 6ft. Then take into account 5in beams and a few more inches of wooden paneling thickness you're left with a little over 5ft width worth of corridor. Plenty of room to walk around in, but it would be completely cluttered if it had furnutre in it. Besides, none of Olympic's or Titanic's accommodation plans show any furniture there at all.
Regards,
Daniel.