Alright kiddo, do you know what a dreidel is? It's a small toy that's often played during the Jewish holiday of Hanukkah. It's a spinning top and has four sides with different symbols on them - a Hebrew letter on each side.
Now, "dreydlekh" is the plural form of dreidel. That means if you have lots of dreidels, you can say you have dreydlekh. It's like saying "lots of dreidels!"
So next time you see someone playing dreidel during Hanukkah, you can impress them by saying "Wow, you have so many dreydlekh!"