I'd try a narrow bench in a medium wood tone that complements the floor and dining table. This sample I think has too many plants and too small, but I'm thinking something like this...

Agree with Darcy...something low and narrow would be quite nice.

Love your plants!

I think the problem is that your plant stands are all different styles which makes the arrangement look quite choppy. I'd suggest that you find a single narrow bench or low table to place in front of your window. It's possible that you could find something in a resale store and you could cut down the legs so you could try it out to see how to see how it works in your space.

In addition, it might also help if you would vary the plants that you place here by height and by leaf color. That would depend upon how many plants you have in other locations in your house. In addition, look around your house to see if you have any interesting containers in which you can put your pots. That would also add to the interest.