Other Inyanei ha-Se’udah

The Rebbe once told Reb Noson that if one intends to be kovei’a se’udah at a second location after beginning the meal at home (such as to join a gathering of chaveirim and to bentch there), one should wash a second time without a berakhah before continuing one’s meal at the second place. He commented: “When Jews go to eat, they always wash their hands first…”
(Si’ach Sarfey Kodesh I, 729, citing a ms. of Rabbi Shlomo Wexler. However, this is a hiddur mitzvah; see Shulchan Arukh, Orach Chaim 164:1.)