Make a conversational cluster...a 12x12 to 16x16 ft sq area that is comfortable for people to sit and talk to each other. So the two side chairs should be pulled in closer. I'd move the sofa toward the center a little more too. Get an ottoman or coffee table. Get some side tables for the chairs so people have a place to put things down. If there's room for a sofa table and some lamps on it do that behind the sofa to help separate the dining from the living area.
When changing the light over the dining table, hang it so the bottom of the fixture is 30" above the table surface.
Here's an example of the conversational cluster.
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Cornice
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