Those applications seem pretty weak. In a similar timeframe I seem to recall possessing a standalone dictionary/crossword solver device, and a five-language translator/dictionary. Both of which were much more compact and presumably had small, solid-state data in ROM chips. The monochrome, text-first Data Discman software looks similar to the output of those basic devices.

I suspect the problem with the Data Discman was weak multimedia capabilities, compared to the what can fit on a CD-ROM, in either its API or what the hardware could push. If the software of the Data Discman had been more like Microsoft Encarta, it might have wowed people.