For establishing connections to Excel files, I’d strongly recommend to use Excel as a data source option. In [Excel Sources](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/creating_data_sources_and_base_views/excel_sources/excel_sources) of the Denodo documentation you can find a detailed description on how to create Excel data sources.
The limitation referred to is the bottom one. So, Excel drivers versions newer than 2003 can execute multiple queries simultaneously.
Hope this helps!