Yea that is kohlrabi specifically superschmeltz kohlrabi. If you let Vienna get that big it will have the texture and taste of tree bark. For fresh eating it’s hard be beat simply slicing it thin and eating it raw with a bit of salt. It taste sort of like a fresh cauliflower or a turnip.
Most of it will get cubed up into 1 inch ish pieces the blanched and frozen in quart size bags. When I’m ready to eat it I put it into the steamer for 30 minutes to thaw and start to cook then it goes into a casserole dish with butter, cheese, and bacon bits if I have them and cooked until it’s fork tender. It tastes a lot like broccoli when cook that way. My broccoli always goes to seed and kohlrabi always grows well here so every year I plant less broccoli and more kohlrabi