Hi, I would say that it's a rule that your model names are singlular and your table names are plural within rails. If you follow the rule set forth, then life is made easier. Also, it was design to be English like if you read the model's associations.
Next, we don't explicity reference the tables names within the models but we setup associations to other models using the proper syntax.
Finally, you're free to use non-standard table names as well as turn off pluralization within rails.