Pour 2 cups water into a small sauce pan and bring to a boil over medium-high heat. Reduce the heat to medium and add the quinoa. Cook stirring regularly, for 10 to 15 minutes, until all the water has been absorbed and the quinoa is tender. Set aside to cool to room temperature.
To make the herb dressing, place all the dressing ingredients in a small screw-top jar and shake well to combine.
Combine the quinoa, tomato, crab meat, arugula, and dressing in a large bowl. Cover and refrigerate for 20 to 30 minutes to allow the flavors to meld.