Hi JP thanks for posting in the Lucid community! The "Refresh" option is only available when data is linked from Google Sheets as it requires a live dynamic connection to your data source. Since the Excel file is a static upload Lucidchart is unable to access and update the data with any changes you may have made to the original file that is stored locally. In this instance I recommend either replacing your dataset by uploading the newer version of your Excel file or converting your Excel file to a Google Sheet and establishing a connection from it to your Lucidchart diagram so that you're able to dynamically refresh it. Please let me know if you have any additional questions about this! 

Hi, JP! I know this is an old thread, but I wanted to let you know that we are actively developing an Excel integration with Lucidchart. This feature will allow you to import spreadsheets from Office 365 business accounts, and have 2-way syncing between Lucid and your Excel spreadsheet. 

If you (or anyone reading this) is interested, shoot me a DM. I can get you onboarded to our Excel beta.  We’re actively looking for testers that can provide feedback and feature requests for this new capability.