Massive Excel Table - Tips please

Hi

My spreadsheet is now pushing 250k lines consisting of 20 columns of data.

Every month I have to add a new months worth of data to the sheet (approx 4k lines) and I have to refresh the last 3 months data.

So i delete the previous 3 months and then add them back in along with the new month.

This is proving tedious, Excel hangs, does not respond and crashes quite often.

I know I need to put it into some kind of access document but really not sure the best way to go about it.

Can anyone give me any advice?