Do you know the Bumlebee package ?
It is well documented, and has a lot of nodes to read/write from/to Excel.
https://konradsobon.gitbooks.io/bumblebee-primer/content/110_read_data_from_excel.html
http://archi-lab.net/bumblebee-dynamo-and-excel-interop/
Also searching this forum wil get you a lot of information, like the link below.
https://forum.dynamobim.com/t/revit-to-excel-to-revit/10469/2?u=mjb-online
Kind regards,
Mark