Monty Hall expo,
Monty Hall was the host of Lets Make A Deal, a popular American game show. An expo is a display of businesses at a convention. In other words, Ghost is saying he makes big deals.
Probably also a play on the baseball club Montreal Expos, who in 2005 moved to D.C. and became known as the Washington Nationals.
To help improve the meaning of these lyrics, visit "Mighty Healthy" by Ghostface Killah Lyrics and leave a comment on the lyrics box