Electrical Appliance Killing Extension Leads
You'd have to check the rating of the saw, but I suspect for the cheap power strip, it's just a matter of being cheap.  

However, for the coiled up spools, it's a different matter. 

It's the Yanks

You know in the 1940s when America helped out?  One of our electricians must have left behind a copy of our Electrical Code.  

If a 2 metre power strip would reach the saw, I gather you were only using 2 of the 10 metres of the coiled up cord.  That meant 8 metres on the spool.   Figure 160mm  spool diameter times pi is 500mm, so 2 coils per metre or 16 coils.  Each side of the coil has 16 cables or 32 active conductors.  

Anyway, that old Electrical Code says about conductors in confined spaces:



So 32 conductors calls for a 40% derate... The spool is rated 10A.  Derate that to 40% and you have 4 amps before you start overheating wires.  Wow, that‘s kind of a stupid product, isn't it?

I'm guessing your saw is a fair bit bigger than 4 amps.  (You'd have to check). 

The proof of the pudding is to unspool all 10 metres of wire and search it for thermal damage.  If you can't even unspool all 10m, that means the coils are melted together.  That is often the case when coiled electrical cords are used near limit.