Save a large spreadsheet as a package in Numbers on Mac
By default, Numbers saves your spreadsheet as a single file. If your spreadsheet is over 500 MB, Numbers may perform better if you save the spreadsheet as a package.
Save a large spreadsheet as a package
Save as a package file: Click anywhere in the spreadsheet window to make it active, then choose File > Advanced > Change File Type > Package (from the File menu at the top of your screen).
Revert a package file to single-file format: Choose File > Advanced > Change File Type > Single File. You may need to revert because some web or email services don’t allow you to upload or attach a package file.
See the Apple Support article Save documents as a package or a single file for more information.