(covers information from several alternate timelines)
The Vidiian ship was a massive starship utilized by the Vidiians in 2371 and 2372. This class of vessel operated with a crew of well over three hundred, and was armed with hyper-thermic charges and grapplers, which was used to access captured ships.
After Kes from 2376 visited an alternate 2371, she betrayed USS Voyager by contacting a Vidiian ship in exchange for transport back to Ocampa. The Vidiian ship herded USS Voyager towards a subspace vacuole and into an ambush. Though Voyager was damaged by the attacking ship, it was defeated in the ensuing battle. (VOY: "Fury")
In 2372, the USS Voyager was attacked by such a ship when it was trapped in a plasma drift. At the time, Voyager was experiencing the effects of a subspace divergence field, which effectively created two ships, one of which was unseen to the Vidiians.
The Vidiians attacked one of the Voyagers and destroyed its weapons array, before maneuvering the ship into grappling range and boring an access route through Voyager's hull on deck five, before Voyager was boarded by over 347 Vidiians.
Knowing that her ship was doomed, Captain Kathryn Janeway rigged Voyager's auto-destruct, which destroyed the Vidiian ship and allowed the other Voyager to escape unharmed. (VOY: "Deadlock") Later that year, when Harry Kim suggested to Tuvok that they should contact the Vidiians in order to help find a cure for a virus contracted by Janeway and Chakotay, Tuvok reminded Kim that Voyager was recently responsible "for the destruction of a Vidiian ship, an act which killed over three hundred of their people. That alone makes it unwise for us to contact them." (VOY: "Resolutions")
According to the final draft of the script for "Deadlock", the ship's bridge was described as "a small, modular room with an emphasis on isolation. No main viewscreen. None of the open, "communal" feeling of most starships."
According to the script notes, this vessel was described as "massive", as compared to the "smaller Voyager."
For more information on this CGI model design, please see VOY studio models.