I have tables created from linked Excel files.
My workflow is as follows:
I import the Excel file with Unformatted Table and my chosen Style applied during import. After i import it, I assign the top row as a header row, and various other rows as subheader rows with other styles I have. Some tables I'll go further and manually add certain styles to certain cells.
But when the original linked Excel file gets changed, and I go to update the link in InDesign, all of my applied styles and formatting are gone and I have to redo everything.
Is this the nature of linked Excel files? I was really hoping to just have the data update and not having to re-apply all of my styles again.
Yes, that's what happens unless you use Table Styles and Cell Styles.
Not only do you have to use AND Table styles AND Cell styles, you ALSO have to use Paragraph styles in those Cell styles to keep formatting when updating/re-linking!