Unfortunately, an extract is kind of like the Hotel California - data can check out anytime it wants, but it can never leave.
That's actually an overstatement, but it won't be straight forward. You'd need to:
- Build some sort of Tabular Report which shows the columns and rows
- Export same as text or a cross-tab cross-tab
The challenge here is that Tableau isn't built to create massive tabular reports. You can only show 16 distinct columns at a time. SO, you'd need to build 4-5 COPIES of your report, each showing a different 16 columns, export each one, and then "paste" them back together in Excel somehow
Where did this data come from, anyway? Seems like you'd almost have an easier time of it if you went against the "real" data in it's native source vs. trying to pull it out of an extract.
I expect that you've tried this: Clicking the data source > View Data > 100,000 lines and copy / paste to Excel?
You might have to wait a few seconds for the copy and at some point you'll hit a size limit for the clipboard (1/16th of system memory??)----50K rows * 67 cols seems like it might fit.
But I agree with Russell, that you're probably better off going back to the pre-extract data source.