Drain the tofu - Press the tofu by wrapping it in a kitchen towel and placing it on a rimmed plate. Place a weight on top of the tofu and let it drain for about 30 minutes. You can use a cast-iron skillet or anything heavy that can be easily balance atop the block of tofu.
Mix the dressing - In a smal bowl, combine the mayo, zesty zucchini relish, vinegar, mustard, sugar, turmeric, dill and parsley, and salt and pepper. Mix well.
Prepare the veg - Slice the celery stalk lengthwise so that you have 1/2 inch strips, then thinly slice the strips crosswise. You want the texture not just the flavor of the celery. Grate or finely mince the onion.
Crumble the tofu and combine with the other ingredients - Crumble the tofu with your fingers. Stir in the onion and celery, then mix in the prepared dressing. Chill for a few hours before serving.
Notes
Zesty zucchini relish is so good, but you can substitute sweet pickle relish if need be.