These sort of policies are never a good idea as the cost is a too high percentage of the cost of the article purchased. Unless you are a very unlucky person just be "self-insured", or consider incorporating gadgets like the Kindle in to your house contents insurance.
Beware this SIM does NOT work in a 3 mobile wifi dongle ! - and the instructions do not say so. My Kindle pad just shows an error message - "replace in a mobile phone --- etc. " If not usable in a dongle the instructions should specifically say so.