BEETS… large tops but small marble sized roots?

Question

Added organic fertilizer, organic bone meal. regular water

Answer 1

It could be that they are too close together; not properly thinned.
If they have been thinned as seedlings and still are not producing; it could be excess nitrogen.
A soil test is the only way to know if this is the issue.

https://www.gardeningknowhow.com/edible/vegetables/beets/beets-small-or-deformed.htm
https://www.gardeningknowhow.com/edible/vegetables/beets/growing-beets.htm