If your family eats fruit anyway, a bowl placed on a narrow fabric runner on the table to display/serve a few pieces of fruit might be appropriate.

You could add a modern, shallow, rectangle box shelf beneath the windows that is the width of the windows and paint it your favorite warm cheerful color -- or painting just the interior of it an accent color but paint the outside the same color as your wall.

Depending upon how much room there is and, perhaps, whether or not you could turn your table so the narrow end aims at the windows, you might consider adding a waist high room divider cabinet with doors for hidden storage between the dining area and the area on the right.

Here are some ideas to add color and texture. Place artwork under the window to accent the green in your chairs; add texture in a light fixture and as a table centerpiece. Try a search on Houzz for clerestory windows in dining room to get some other ideas.

Rug and art I like the table & chairs

We think all you need is some art to go under the windows. You have a great dining set. Simplicity is key here.