Can/should I use scripts as classes?

So I was reading this guide: http://howtomakeanrpg.com/a/classes-in-lua.html And it showed off a fancy way of turning a table into a class, but why not just use a script as a class and add all the methods and variables for Orc to that?

name = "Orc"
maxHealth = 10;
currentHealth = maxHealth;
damage = 2;
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function TakeDamage(amount)


end

function Attack(mob)
    mob.takeDamage();
end
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function Start()

end

function Update()

end
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Start();
while(wait(1/60))do
    Update();
end