In the eighties, it was 'de rigeur' to have a filofax and a mobile phone. That's mobile in the same way that a 20 inch telly is mobile. This was the age of the yuppie, or young upwardly mobile professional.
The term referred to people usually in their 20s and 30s, in the upper middle class, who had good jobs in the city, often in the stock market or advertising trade. This is why the term largely faded from use in the late 80s after the big stock market crash.
Until then though, the yuppies made the most of their newfound wealth and social status. They gained a penchant for the finer things in life - wine over beer, designer ice cream, gadgets, jazz music and designer clothes - albeit is a brash, ostentatious way. Of course, the most visible trademark of the yuppy was the brick like mobile phone that seemed to be permanently stuck to his ear, as he was very very busy, didn't you know?
Being so busy, meant the yuppie loved all things that made life easier, including the Filofax for organising all those business meetings and wine bar visits. Mail order catalogues were popular, as was recording their favourite TV shows to watch after a long night in the office and the life-saving answering machine as they were never at home.
In all, yuppies were hideous, unless you were one.