problem with excel spreadsheet
I have been using a spreadsheet on excel which has become increasingly slower to the point now that it has become unusable. If I search the data I have enough time to put the kettle on before I get a result. I'm not sure but think the formatting is slowing it down but I don't know how to change this. For example one column is for entering names. If I start to type SM (for Smith) then all the names on the sheet that start with 'SM' come up on a list. This makes me think that, for lots of cells, there are is formatting that is looking in lots of other cells and this is slowing things down to the point that the sheet is pretty much a write off.
How can I remove the formatting or speed it up?
MacBook Air 13", macOS 10.15