Afton, it would help a great deal if you'd post a plan of the room with measurements and all openings (windows, doorways, etc).

How many people do you need to seat regularly? Is there anything else you need/want in the room besides table, chairs, and sideboard?

When you say "the rest can go", what pieces do you mean?

I see a toy truck, so I'm going to mention now that my favorite kid's chairs are from Ikea, either the Ingolf or Agam. Keep those in mind when you look for a table and chairs so you can co-ordinate one or more child's chairs.