Some physical things that we own can be reduced to information – i.e. digitised. These include CDs, DVDs, photos and increasingly books.

The advantages of making these sorts of things digital include;

Robustness - if your house is burnt down / blown away / washed away then you will have lost all your CDs, photos and books, but if they are in digital form then it's easy to keep a backup copy somewhere.

Portability - a thousand CDs are difficult to carry around and so will only be available when you are at home. But a thousand albums on a portable media player will be available far more of the time. The same is also true of photos and may one day be possible with books.

Updates - a traditional multi-volume encycleopedia is big, heavy and expensive. The digital equivalent fits on one DVD-ROM and costs a lot less. Both of these will start going out of date as soon as they are printed but an 'online' reference will be regularly updated.

In the old world of analogue, a radio and record player were used for live and pre-recorded audio and a television and video recorder used for live and pre-recorded video.

If a NAS (network attached storage) box is used together with a 'smart' TV and a WiFi radio this makes an elegant setup for audio and video. The radio can be used to listen to live audio from radio stations via the aerial or the internet. It can also be used to listen to pre-recorded audio either from the internet or from your own collection - stored on the NAS box. Likewise the 'smart' TV can be used for watching live video recieved via the aerial or the internet and prerecorded video from the internet or the NAS box. And, when not at home, you can play the content on the NAS box on a laptop or tablet via the internet.
This setup has a problem - some current smart TVs can record to a storage device connected to them via USB but none can record to a NAS box.

What is a tablet good for? Replacing some things traditionally printed on paper.

A tablet makes a good dictionary. Searching for a word can be quicker and some app's can play audio of how the word sounds when spoken. However, some dictionary app's only work with an internet connection.

A tablet makes a very good replacement for local business directories, with app's providing the same information. Again an internet connection is needed for the app' to work.

A tablet can, to some degree, replace a newspaper.
Newspapers on tablets take two broad forms - app's that download the articles as you want them and editions that are downloaded for you to read them at a later time. So, the first kind needs an internet connection whilst you read it, the second needs an internet connection once a day.

Viewing photos on the screen of a tablet is a lot better than on the smaller screen of a digital camera or mobile phone. The screen of a tablet is a similar size to a paper photograph from recent decades and shows a similar amount of detail. It also takes up a lot less space than a few years worth of photo albums.

Whilst the Freeview App makes a good TV guide, the particular model of tablet pictured (a Galaxy Note 8) has an infra-red transmitter which together with an app called "Samsung WatchOn" makes a pretty good replacement for a TV guide magazine and TV remote control. You can browse through what's on now, see details for a programme and change to that channel (withought having to put in the channel number) which works great.

Thick heavy paper catalogues of products to buy are bettered by apps that let you more easily find what you want and browse through alternatives.

Tablets and portable DVD players have similar sized screens and will both play videos. With one you have to carry around the DVDs that you might want to watch, with the other you have to 'rip' those DVDs to the tablet or a memory card. 64GB will hold about 10 DVDs in the original format, or as many as 90 if you don't mind losing some quality/resolution.

Watching films 'on demand' requires a connection to the internet. Downloading films from the Play store/iTunes/xbox video is no less expensive than buying a DVD or BluRay. When you've downloaded a film to one device it might be tricky to move it to another. And once you've done with it you can't give it to a friend or charity shop and so you can't buy them second hand.

Equipment manuals? QR code on equipment links to PDF.

Books? Colour E-Ink display, DRM / distribution .

Calendar - like the one you hang on the wall, except you can't hang it on the wall but it does update/sync with the one on your smartphone.

So, put together all the things a phone and tablet can replace and you have the assortment pictured:

A portable DVD player and some DVDs, a star chart, shopping catalogue (Argos), dictionary, local business directories (Yellow Pages and Thomson Local), video camera, stills camera, telephone, pocket watch, dice, sound level meter, newspapers, photo album, TV guide and remote control, portable games console, modem, alarm clock, torch, stop watch, notebook, address book, diary, calculator, dictaphone, compass, sat' nav' radio and MP3 player.

Usefulness = (Functionality x Availability) – Burden