The Coffee Table is quite mobile, moving as fast as a Pork Bean, and also acts somewhat like a horse. One of these tables are secretly sent to Lucas by the Mr. Saturns after Saturn Valley is overrun by the Pigmask Army. The two must ride the table to the valley where Duster and the Saturns are being held hostage.
The table is no longer needed once Duster rejoins the party, and is effectively replaced by a redesigned Pork Bean.
In Super Smash Bros. Brawl, as well as Super Smash Bros. for Wii U & 3DS, Lucas's stage intro has him ride in on the coffee table.