'That'll do Tom'

In the context from which this quote was taken, it could appear, superficially at least, that Judge Taylor’s foremost concern is the efficiency of court proceedings.  While to some extent I’m sure this is true, I believe this situation was contrived by Harper Lee in order to demonstrate Judge Taylor’s sympathy for Tom.  With only a small statement, Lee illustrates Judge Taylors respect for Tom, and his desire to preserve his dignity.