In Voyager’s transporter room, there is an alcove on the side, and embedded in the wall is what appears to be a small transporter pad. I don’t believe anyone is ever shown interacting with this, so there’s no definitive explanation for what it is. Assuming it is what it appears to be, what would be the purpose of a very small transporter like this?
My best guess is that it’s either for samples from the surface (though we have seen multiple cases where those were beamed directly onto the main pad or in the cargo hold)
OR
possibly a tools or weapons grade replicator.
The transporter is a vital component on the ship like the engines and requires constant maintenance so maybe they figured it was easier just to have something like that in there to make quick/easy access for replicating the tools they needed when/as they needed it instead of lugging it around.