As of the original publication date in January 2012, my little herb garden was sitting in a $1.49 black plastic drain tray with inside dimensions of 20 inches long X 10 inches deep X 2 inches high. While not elegant, this tray did a good job of keeping my herbs organized and was easy to move my little garden around to light sources or heat sources.
But this tray will hold two more 4 inch square starter pots and a couple of the small 2 inch pots. Or it could be configured similar to the tray in the illustration above with the Rosemary in a 10 inch or 12 inch pot combined with the Thyme or with the Marjoram. Parsley would need a separate pot because it likes moist soil and sunny to part shade conditions.
At present I have these herbs in my garden; Greek Window Sill Basil, Italian Flat Leaf Parsley, Triple Curled Leaf Parsley, Marjoram, Tuscan Blue Rosemary, BBQ Rosemary, Thyme, French Tarragon and two garlic chive plants. They are in 5 and 6 inch pots so they have room to grow and spread out.