I would point out that in the U.S. the lowest governing body with courts is the State Government (county court houses are just the local branch of the State Court and usually in the county seat aka the town where county level government operates). Small Claims courts are state level courts for suits that don't exceed a set dollar value in damages (Usually <$5000 not including attorney's fees). A similar criminal court may be called a Magistrate and is used mostly to argue crimes like traffic tickets and the like.
Your Perry Mason example is not an example of small claims courts but rather small town courts and the Urban/Rural divide in America. A good number of political issues in the U.S. are brought about by Urban dwelling population not having a good understanding of the needs of rural communities and vice versa and this is historically been a long standing divide in American Politics. The court is small because it's physically small and the cases it handles are quite mundane, boring, and infrequent compared to a courthouse in L.A. which is larger due to the more numerous cases and more dramatic due to the frequency of unusual events in the case. Rural courts, especially, do tend to have a large section for the galley as back in the day, (i.e. before TV) watching a trial was sometimes entertaining.
As to the objections getting overruled, that's not a small court issue, but a judge issue. Judges are allowed to rule as they see fit and if they're wrong that argument is had on appeals, not with the trial judge. There's an old lawyer adage that "Good Lawyers know the Law, Great Lawyers know the Judge" which essentially means knowing how the judge would rule in a certain matter allows you to better develop your planned argument to present to him/her. Mason is at a disadvantage here because he argues in Los Angeles, not Podunct, CA, and thus doesn't know this judge as well as the ones in LA.
Small claims and Magistrates tend to be less formal because they tend to be quick and the law is well developed... often times both sides don't have lawyers and the money isn't great. In other examples, such as Judge Judy and similar shows, you're not really watching an American Court room Judge, but an Arbitrator (Judge Judy) ruling on binding arbitration between two parties (i.e. rather than go through the court process, they present their case to an arbitrator who hears the arguments, makes a decision, and if both parties respect it, it's over and can't be appealed... the winning party can however take the matter to an actual court if the loser fails to uphold his/her end of the arbitration). Almost every daytime reality court show is actually binding arbitration and on Judy at least, there are a few times where she dismisses the case because IT SHOULD go to a real court. For what it's worth, Judge Judy is an actual Judge, although when she was on the bench, I believe she dealt with family law.