I always find it interesting to look at future history – that is what people imagined the future would look like years ago. The two screenshots here came from Star Trek Deep Space 9 season 6 episode 9 (Statistical Probabilities) which first aired on November 24, 1997. In 1997, the touch screen Newton was on the wane while the Palm Pilot and Windows CE Handheld PCs were on their way up. Apple’s Newton was probably the closets thing we had to a tablet device.
Meanwhile, the PADD tablet devices first seen in Star Trek Next Generation were commonly shown on Star Trek Deep Space 9. In this particular episode (S6E9), PADD tablets were used like paper pads. There are several scenes where different aspects of the result of statistical research was shown on multiple PADDs.
While this was probably done to illustrate the complexity of the analysis at hand, some of us do something like this today. It is not unusual to see people with an iPad (or some other tablet) on a table and a smartphone in hand checking email or other information. The reason I do this is to avoid moving away from the current display on the iPad. I sometimes also have a notebook (or desktop) open along with an iPad and smartphone.
Just as having multiple displays on a desktop is very useful for many people, having multiple mobile devices to look at different information aspects is useful too.