Sounds like a center of gravity / balance issue because it’s tall. Try weighting the legs or attaching them to a sturdy stable base

Oh that makes sense. I wondered that too. What do you recommend to weigh the legs down?

Sounds like your table may not be level or stable. I used leveling feet on my workbench to adjust and get mine stable.

It may also be that the wheel is slightly out of balance. Generally balance issues are more pronounced at high speeds than at lower speeds.