Maybe I am missing something, but I don't see the analogy. When I
indicated the table surface I zeroed the indicator at one point on the
table and then traversed the table back and forth and in and out to get
the readings over the complete surface of the table. I believe that
this indicates the flatness relative to the column. To use your
bicycle wheel analogy, if I held a bicycle wheel under a dial indicator
and moved it right and left and in and out, I certainly would know it
was not flat. Maybe we are saying the same thing in different ways.
All I am saying is that if you get an identical indicator reading over
the entire surface, then the table is flat and is traveling in the same
plane both longitudinally and crosswise. If the indicator readings are
not the same the problem can either be the table is not flat or the
ways are not correctly oriented.

I did not invent this test. It is how the K.O. Lee Rep told me they
make their check, and it is clearly spelled out in Machine Tool
Reconditioning.