As the examination begins, Atticus’ table is bare. What does this show us?

The circuit solicitor and another man, Atticus and Tom Robinson sat at tables with their backs to us. There was a brown book and some yellow tablets on the solicitor’s table; Atticus’s was bare. Just inside the railing that divided the spectators from the court, the witnesses sat on cowhide-bottomed chairs. Their backs were to us. 

Atticus's table is bare. One might say this is not a significant detail. But consider the symbolism and what it does show us. Tom is facing an uphill battle. Although he is being tried in a court system which is praised for its "innocent until proven guilty" mantra, Tom must deal with a jury of his white peers who still hold racist thoughts. From a more broad perspective, Maycomb, the South, and (to other extents) the rest of the country are all still pervaded by institutional racism. So, the bare table could symbolize Atticus's hope for a clean slate. Ideally, the jury will wipe clean any racist notions they have in their minds. None of that baggage should be attached to Tom. The table is a "tabula rasa." This is a philosophical notion that means "blank slate." Therefore, the blank table represents an ideal: no preconceived notions of racism. Atticus hopes the jury will do their job with this principle in mind.