Tabs in Excel Online worksheet move unexpectedly

Mine continue to behave themselves.   I hit another problem, and I don't know if it had anything to do with setting the stage for the perigrinating pages problem -- my workbook hit a size that triggered a warning from Microsoft that the workbook was almost too big.   Mine is an order system that breaks orders down into products and products into parts, generates a pick list of parts and updates the parts inventory by subtracting parts as they are ordered by customers.   The accumulation of orders makes it grow (each order is a page).  So I had to give it a fresh start, saving it with a new name and deleting all the orders to date, after creating one fictitious order consisting of all the parts ordered to date so that the running total would be accurate in the new workbook.  Then came the question of how to delete 200 pages without having to do 200 separate delete operations.   The solution was to download it to desktop, which has the functionality to delete a range of pages by highlighting the first one in the range, holding down the shift key and highlighting the last one in the range and then hitting delete -- something you can't do online.  Then I uploaded it back to the online version. CScott20