Mpasua Msonobari is the name or pseudonym of an online translator for translatorscafe.com.
Background on the name:
Kupasua (inf.) means to split, to chop, to cut: kupasua kuni to chop firewood, mpasua mkuni one who splits firewood.
Two online dictionaries (goswahili.org and africanlanguages.com) say msonobari is a pine tree; other online dictionaries do not have entries for the word. The Standard Swahili=English Dictionary spells the word with a U, msunobari, defined as imported pine timber.
So mpasua msonobari means a person who splits pine lumber or chops down pine trees.