This salad feels fancy and cross cultural, although all of its ingredients are available in most any market--even now. Some may find it reminiscent of a salad at a French bistro, while I was pulled towards memories of dishes conjured up in Berkeley and Oakland because of the avocado (adding citrus to the dressing would tip the scale to California cuisine). Either way, it is simple and delicious.
Place the tomatoes on serving plates or a large platter in a scattered single layer. Cut the avocados in half and remove the pits, then remove the avocado flesh, cut or tear it into pieces and scatter over the tomatoes. Distribute the crabmeat evenly over the tomatoes and avocado, breaking the larger chunks up a bit. Mix the olive oil, tarragon and some salt in a bowl with a spoon, then drizzle it over the salad. Sprinkle a healthy amount of salt over everything as well, before serving at room temperature.
Orange or grapefruit segments are a wonderful addition to this salad. Roughly chopped toasted almonds also add some nice texture to things.