Hi Norman Jackson,
Good Day. I hope everything still fine. Im Jhun an independent Advisor. Lets try to do some troubleshootings and try to solve your Excel lagging/freezing issue.
First, try to close excel completely. Swipe up from the bottom of the screen>hold> and swipe off the Excel on the screen. Reopen and test again.
Second, Clear Excel's cached data. On Settings > Excel > Reset Excel > Reset Settings. If it does not delete your files just reset the app configuration.
Third, check for the latest update and make sure Excel and your Ipad's OS are fully updated. Microsoft usually quickly release a fix when a massive freezing issue occurs.
Fourth, try to disable your autosave or i-cloud temporarily. Try to open a locally saved file on your device and try to test it.
Fifth, try to use Excel in Airplane Mode. This is to test if it works without background syncing or cloud files.
Sixth, try to fully restart your Ipad. Also check for the free storage spaces on your device (atleast must have 2-3 GB free remaining space).
I hope one of the steps above will solve the issue.
Regards,
Jhun