Ram-Don was completely made up for the film for English speaking audiences. They actually say Jjapaguri (or Chapaguri) which is a portmanteau of two types of Korean instant noodles, Chapagetti and Neoguri. The subtitle translator found that Jjapaguri was difficult for English speakers to understand, but they would likely be familiar with the Japanese noodle dishes, Ramen and Udon, so she combined them into Ram-Don.
It’s doesn’t change the meaning too much, but I do take some issue with going from Korean to Japanese in the translation, kind of lumping different types of Asians under the same umbrella, especially since Jjapaguri is a uniquely Korean Dish. But I know people have differing opinions on this.
BONUS: That whole scene also subtlety illustrates the film’s theme of classism as well because Jjapaguri, is more of a cheap, comfort food. But Mrs. Park insists that sirloin is added, changing it into this fancy meal. There is another mistranslation here. Mrs. Park actually calls it “Hanu” (loosely meaning premium beef, similar to Japanese Wagyu in its reverence). Using sirloin, while not being a cheap cut of beef, doesn’t accurately reflect the significance of using such a high quality meat. The fact that the family can afford to use such premium beef in instant noodles so casually shows how wealthy they are. Jjapaguri is not an marker of wealth, but putting Hanu in it, definitely is.