Those beetroot look good.
What variety is that?
I have tried all kinds over the years but always fall back to my trusty Boltardy and Egyption.
I thin mine out and transplant some and they never seem to mind.
I tend to try and space them 3-4 inches apart if you want baby beetroot or 5-6 inches if you want them larger.
I sow mine in regular sowings from March to late Summer.
As well as fresh, I also freeze them whole and in sliced crinkle cut slices, no blanching after a roast for 45 mins in the oven. I also pickle a load in jars, with Sarasons classic malt pickling vinegar, so they only have a mild pickling taste, just how we like them.
As above, the leaves on beetroot are tasty, you can pick some of the leaves as the beetroot is growing.
