It does have a micro SD card slot. It is also possible to replace the main M.2 drive with a larger one, I have 2TB in my Steam Deck.

I have it deployed at work for my 55 users instead of getting Microsoft Office licenses for all of them. They are not sophisticated users and it suits their needs. I probably field a few more questions for it than MS Office but they would call about that too since they think I am Google.

I personally think that Calc does a better job handling various CSV files than Excel.