Solution
The easiest way to read the contents of an .xlsx file is with the
NI_Read XLSX File.vi solution provided in
this post on the LabVIEW Community forum. This VI does not require Microsoft Excel to be installed.
Some alternatives to read
.xlsx files include the LabVIEW
Report Generation Toolkit or other 3rd party toolkits, although most of these approaches require Microsoft Excel to be installed.