Q. Can one talk in-between washing for Karpas and eating it?

A. Mishna Berura (158: 20) rules that when we wash netilas yodaim for food that is immersed in liquids before consuming, although we do not recite a blessing on the netila, we should be careful and observe all details usually kept on a regular netila for hamotzi.
Many don’t wash this netila during the rest of the year and especially when a fork or spoon is used or the amount eaten is less than a kezais, as we normally do with karpas. Yet, Shaarei Tzion (473: 69) quotes that Acharonim maintain that in the night of Pesach one should be stringent and observe this netila, the reason is to arouse the curiosity and encourage the children present to ask why.
Chakal Yitzchok (Hagada) mentions that even the calling aloud of the simanim of urchatz and karpas, should be done before the netila or after eating the karpas. However, others maintain that this is not a hefsek. (Vayaged Moshe 24). Otherwise, the seem to agree that one should not talk and be mafsik unnecessarily between urchatz and karpas. (See Piskei Teshuvos 473: 21).
Horav Shlomo Miller’s Shlit’a opinion is similar.

Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit’a.