I don't think so. We always see the PAD running the same application/GUI which seems to be an all-in-one reader supporting video, photos, and text. I can't remember any instances of the PAD being used for much more. Not even audio/video chat which was reserved for the personal communicators and wall/desk consoles. At one point we see Picard's desk covered with multiple pads further suggesting they were uni-taskers. Multi-tasking certainly existed in the 80's so the vision of future technology in Star Trek TNG seems to be one of mainframe computing, data in the cloud, and multiple specialized task-centric devices (personal communicator, tricorder, PADS) and good ole' fashion desktops (consoles) being used for more advanced tasks.