To be honest - I have no frigging idea how he got it that big. I think one of the issues is that they dump huge .csv files out of our ERP system, then they bring the .csv files into Excel. If you don't save it as an .xlsx before you start screwing with it, Excel doesn't optimize the file - and .csv files are waaaay bigger than the corresponding Excel file.
Also, they don't have just one sheet. They dump these huge .csv files, that have hundreds of columns and a bajillion rows, then they try to load 3 or 4 of them into Excel at the same time and then have other sheets that combine data from the source sheets. We had to install 64 bit Excel to try to keep the thing from corrupting the files. This particular guy is one of those really annoying business managers - he thinks he is waaay smarter than he really is - and if *your* computer can't do what *he* wants it to do, well that's *your* problem. I have told him repeatedly that we have a $2 million ERP system that is sitting on a very nice Oracle database - and databases are *made* for joining tables and doing queries - so, gee - why don't you simply define the report you need and we'll let the database do it for you. His answer is always the same - he needs to "see" the data in order to create the report he needs.
I've been doing this a long time, and I know what that really means - it means the data his people put into the system is cr@p, and he doesn't know how to create a clean report from that pile of cr@ppy data. So, instead of fixing the real problem - his own people and his cr@p processes - he wants IT to perform magic on the back end. That just ain't gonna happen, so he spends his weekends pounding his head on Excel, and then b!tches about IT every week.
Oh - and this is the same guy that will go weeks without ever powering down his laptop. He will travel across the country, stay in a hotel, go to the office, then go back to the hotel - then call us at 11 PM b!tching that his WiFi & VPN connection is "screwed up". He never wants to power off his laptop because it takes too long to load those giant spreadsheets.
Now see what you all did? You got me monologing...