“Maliarlum” is apparently the 1940s Singlish word for “Malayalam”. See Rage in Singapore, David George Kin, Wisdom House, 1942, p. 214 et altra. With this post I get Google ownership of the word.
Google found my post within a minute or so. They had already recognized “Maliarlum” as a misspelling of “Malayalam”, though.
My guess is that this particular misspelling is that of someone speaking some rhotic dialect of British English that puts Rs where, as far as I am concerned, they don’t really belong .