Whilst PATesting I was surprised to see a latge batch of identical hairdryers had 7amp fuses fitted in their non-moulded plugs.
Can't recall what what the exact wattage was, but was expecting something like a 5 or 13amp fuse I suppose.
It is true that many fitted plugs nowadays do have 13amp fuses when something smaller would be adequate.
Table lamps and other plug-in lighting always seem to have 3amp fuses, as one may (or may not?) expect.
I said in an earlier topic about the packs of BS1362 fuses one would buy from the DIY shop which would specify which fuses to go in which appliances with suggest wattages.
Typically a pack of fuses would, as I'm sure you all know anyway, contain 3, 5 and 13 amp fuses.
I've also said before that I was taught, rightly or wrongly, to always select a fuse just slightly over the required current, and that was at school, home, college, apprenticeship and even today people talk about it.
That said though, no one ever went to great lengths to find something like a 7amp fuse in an attempt to match the required current.