Save your excel file as CSV and then you can read that file using the file-in node and parse the data with csv node.
And then it depends of the data what will be the best choice of nodes to visualize the data on dashboard.
There is also node-red-contrib-spreadsheet-in though I cannot vouch for whether it works or not.
Copyright OpenJS Foundation and Node-RED contributors. All rights reserved. The OpenJS Foundation has registered trademarks and uses trademarks. For a list of trademarks of the OpenJS Foundation, please see our Trademark Policy and Trademark List. Trademarks and logos not indicated on the list of OpenJS Foundation trademarks are trademarks™ or registered® trademarks of their respective holders. Use of them does not imply any affiliation with or endorsement by them.
The OpenJS Foundation | Terms of Use | Privacy Policy | OpenJS Foundation Bylaws | Trademark Policy | Trademark List | Cookie Policy