While you can use the engine to program “office applications” its kind an abusive use of the engine. IMHO you are better of using Qt C++ as it provides literally almost everything you need to code such programs. A very large amount of apps are written with Qt. If you hate C++, you can either use on of the very good python ports(PyQt or PySide2) or simply another language + framework(JavaEE with Swing anyone?). C# with WPF or WinForms(Though both of them suck compared to Qt or Swing…).
However it is totally valid to use UE4 for that. Just be aware you can hit some boundaries or limitations as the engine is still written for games… since its a game engine 
Therefore its geared toward realtime graphics/game code simulation. Office programs, except visualizers are NOT geared toward that. They can use that resources for other things.