Lovely table and chairs to start with! If you like the wainscotting and panelling then I would repaint the entire lower half the trim white colour and repaint the upper walls a more dramatic colour. What about a dark grey (same tone as the fabric in the chairs?). You can really go with any colour in this room but if you want it to flow that's why I think a charcoal could be good. I think you should lower the chandelier (or replace it if possible with something more dramatic that will show up against the new darker walls - something with white linen shades for example). The main wall is crying out for something - an elegant mirror would be great (can't see the sideboard in the photos). Or artwork (series of three perhaps). Finally, draperies (floor to ceiling) for the windows. You will have a show stopper dining room with just these changes. Good luck from Montreal!

Here's an example of a dining room I did with some of these elements to illustrate my points.