If asking that question is not a sure sign of boredom beyond the point of no return I don’t know what is.
Have you ever been so bored that you’ve opened up one of these apps and just… produced a document of some shallow usefulness?
Here’s a slightly interesting thing you can do in Excel.
Put today’s date in cell A1. Drag it doan to A366, so you have a year’s worth of dates.
Put £100.00 in cell B1. Put “=B1*1.01” in B2. Drag to fill down to B366.
Now put your eyeballs back into their sockets, and figure out a way of increasing your cash by 1 per cent a day 
If you have any text files sitting around on your hard drive, then autosummarize in MS-word can be loads of laughs, seriously. (Though it can take a while.)
I run it on fanfiction every now and then… it’s completely hilarious because it throws out all the plot and characterization, and generally keeps repeating character names over and over, sometimes with sentence fragments (depending on what percentage of document length you have it running on,) and different punctuation. Somehow I find some of the results hilarious.
Dunno if this works on post-Office 97 versions of word, but, type in “=rand(x)” (without the quotation marks, and substituting a number for x) then hit Enter.
Not very… interesting, but it’s something.
You can do what I used to do in Works when I was avoiding writing something or another - discover all the keyboard shortcuts, one Crtl+(letter or number) at a time. Not as cool as some of the stuff here, but it always kept me entertained.
Triple-click in Word selects a paragraph. Not very interesting, but damn useful!