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?
it’s the pattern buffer. Neelix tries to touch it in some very early episode, and Tuvok intimates that doing so might kill him in some terrible way. it’s not unusual to see technicians fiddling with it while in the background of scenes.