Remove the corner chair. Remove 2 of the 3 buffets in the room. Remove the decor items on the remaining buffet table.
Put the 2 pairs of white MCM chairs facing each other, and the wood chairs on the ends.
Measure the room with openings, the table and the remaining buffet. What is on the wall opposite the mirror?
What is in the budget? I suggest to replace the central light with one that is brighter, and then remove the floor lamp. The one in your idea book, with the single Edison bulb, is probably not bright enought to light your room properly. New rug in a modern style you like. Replace the wood chairs or paint them the same white as the modern chairs.
As you replace things, you may get some ideas here for colours. Which of these dining rooms appeal to you, and why? Do you like the bright pops of colour, or the earthy tones? https://www.mydomaine.com/mid-century-modern-dining-room-4778901
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