If your thinking of going down the fruit and veg line how about:
Planting a couple of dwarf french beans - 1 each in two of the side holes, the ball size carrots in the top, and in another couple of the side holes sow some peas - keep them short and harvest their shoots for salads. Sow some red crinkled edge lettuce in a couple of the sides and if you have any spare side holes left I would suggest a tumbling tom tomato plant - that sorts out your veggies and salads sorted and for pudding plant a couple of strawberry plants. Most people have strawberry runners they are wanting to get rid off - these will be perfect.
If you can squeeze in a marigold or two they are companion plants and if you can edge the side of the top with nastursion flower plants these two can also be eaten and the look pretty too!
Hope my suggestion gives you some ideas to try.