I fly for an EASA operator and we follow Transport Canada HOT guidelines, The alternative is the one from the FAA. I have never come across an EASA equivalent document, but I've only flown for one operator so far.
There are several types of table because different fluids (and their brand) have different characteristics and properties, which are also affected by external factors. In my base we know well before leaving the crew room what type of fluid is in use, outstation we're usually told by the handling company or by the de-icing equipment crew on the associated frequency.
Now here comes a real world advice: ditch the 777 for a while, get a good add-on for MSFS2020 that will replicate the light airplane you will do your PPL on and practice with it, especially drills. MSFS2020 is especially great to prepare for VFR navigations when you get to that stage.