I think that you should start from choosing the righ table. It shouldn't be to big or too small but what is most important is should be dissolvabled - to make it bigger when the guest would come and smaller on your everyday life. Try to choose also bookstands and cabinets that would be higher and have a lot of shelves - to give you a chance of putting everything there. And if you want to make it visibly larger you should paint it on light colors - maybe yellow or white and it would look defenitely better than in dark colors.
I hope that this will help just a little bit and personally - i think that you dinning room isn't so small actually.