What are the Twelve tables and what did they help to create in Roman Society?

The Law of the Twelve Tablets did not help to create Roman society. They were compiled in 451 BC and 450 BC; that is, 323 years after the given date for the foundation of Rome (753 BC). Roman society had already been created. What they did was to create better regulations for Roman society. The Twelve Tablets was the first written and published code of law of the Romans. They were inscribed on bronze tablets and displayed at the forum. Their purpose was to establish clear rules which could be known by anyone who could read. Prior to this, laws were either religious rules which were interpreted by the College of Pontiffs (Collegium Pontificum, the highest priestly body) and were kept secret, or senatorial decrees which were unpublished. This situation lent itself to abuse.

The consuls, the two annually elected heads of the Republic, were known for at times altering or making senatorial decrees disappear. Moreover, the consuls, senators and priests were patricians (aristocrats). The patricians monopolised political power and were also large landowners. The plebeians (commoners) had rebelled 43 earlier because of the patrician-controlled state refusal to provide protection against the abuse of defaulting debtors by (patrician) creditors who would imprison, torture and, sometimes, sell them as slaves. Nothing was done about this after this rebellion. Plebeian agitations for clearer rules and protections continued and eventually led to an agreement to create the commission which compiled the Twelve Tablets. These produced procedures for the trial of defaulting debtors which provided a degree of protection. They also set punishments for crimes and rules about property and damage to property, family, inheritance, funerals and the like.