php.activerecord

Your ActiveRecord\Model-derived class has a reference to an ActiveRecord\Table.

When the Table gets initialized (once per model-class through some static function calls), it is told it's model's classname.

Table::__construct($classname)

calls

Table::set_table_name()

Through the model's class name it asks if that class has statically overridden the table name. If not, it uses the Inflector library with:

Inflector::instance()->tableize

which is really just

StandardInflector::tableize($classname)

which underscorifies the name (Inflector::underscorify())
converts it to lower case (strtolower())
then hands it off to

Utils::pluralize()

In the Utils library, you will find the pluralize and singularize implementations, which basically have some predefined plurals for the uncountable items (stuff that doesn't get pluralized like sheep and deer), some standard irregular forms (like child > children), and then some cool pluralization rules ($plural and $singular) that it runs through the regex parser.

Phew.

And remember you can override the defaults back in your model class with:

class MyModelClass extends ActiveRecord\Model {
  static $table_name = 'whatever_it_is';
}