Check out CSV or JSON terms in web search. You can simply import text file into definition and work with it.
I would focus in JSON way especially with great JSwan plug-in (compatible with ShapeDiver) from Food4rhino. It allows you to work with data structure in human readable way.
Agreed with @DanielK1. Importing and exporting CSV will be the best approach for you for the time being. There are Grasshopper plugins for reading/writing excel files, but none support input from or output to streams. Therefore, they are not supported on ShapeDiver. We might develop such a plugin ourselves, but currently this is not on our roadmap.