Thought I'd just look at the pluralisation rules themselves. Lessee... Eloquent\ - sorry, Illuminate\Database\Eloquent\Model.php; Model::getTable() looks like the method. It calls [noparse]Str::plural()[/noparse].
Searching for the Str class I find Illuminate\Support\Str.php and I also see a Pluralizer.php there. That's okay: all [noparse]Str::plural()[/noparse] does is call [noparse]Pluralizer::plural()[/noparse].
As an aside, I'm not really a fan of autoloading classes.
Ah-ha. First there's a list of "uncountable" nouns, which has both "fish" and "sheep", and also "data", "metadata", "equipment", "wheat", "love" and "jedi" (but neither "butter", "rice" nor "hate").
After skipping those words it calls [noparse]Inflector::pluralize()[/noparse].
Inflector? Ah, there's a use statement at the top of the file: [font=monospace]use Doctrine\Common\Inflector\Inflector[/font].
Oh, okay. So it actually uses Doctrine's inflector. So I'm sorry, but your class is in another library.
So I pull doctrine/inflector off of Github, and it's a list of regexes for regular forms, a list of uninflected words (e.g., those ending with "fish" or "sheep", so those didn't need calling out in Illuminate, but also "cookie" for some reason), and another list of irregular plurals (such as "loaf"=>"loaves" and "ox"=>"oxen", but it also has rules that are already catered for by the regular regular expressions, and has the wrong form for the plural of "ganglion").
Since I went to that bother, I put the list of words I had in my post through: it got "flyby" wrong, and to say that the plural of the noun "die" is "dies" is actually right or wrong depending on what sort of die we're talking about.
And yes: I am short on stuff to do right now; why do you ask?