The 3A fuse is due to the way the UK wiring system works rather than what is optimal for this device.
All appliances in the UK have a fuse where they connect to the building wiring, normally in the plug, but can be in a fixed fuse-holder like this device. Somewhere in the process it was recognized that having lots of different fuse values would be confusing and awkward for users, so these fuses are the same size and always one of three standard values: 13A, 5A, and 3A. As noted elsewhere, you can buy these particular fuses in UK supermarkets and convenience stores.
If 3A is too high for the appliance then what the designer has to do is to fit it with a flex rated at 3A so that is protected by the fuse at the plug-end and then add additional, lower current, protection at the device end.
The UK system is clever and has subtle details like the standard fuse values which were good at the time it was introduced. But, it is also rather over-engineered, and not optimized for modern homes that have a lot of low-current appliances.
Oh yeah the UK system.. I lived in Ireland for a long time and it was a bit archaic sometimes.
I like the idea of fuses in every plug, mind you. Because some equipment just can't be trusted. I didn't like the switches in every outlet (even though they're not mandatory, they are very common). And the way the plugs are so huuuge and always fall with the pins up do to the design so they are a foot-piercer.
In Ireland 1A fuses were available though even in the fuse kits in Tesco. With the same size as the others. And the practice doesn't always lead to actual safety, I've seen a lot of tinfoil and paperclips. Yes, really.
But the thing I really thought was the worst was the concept of having only one tap connected to the mains water line in the house, and having all the others fed by a huge dirty water tank in the attic, full of dead insects brewing away in the summer heat (yes even there it can get hot in summer). It seems like an ecological disaster and locals were always warning me to not drink the water from the bathroom or bedrooms taps. It's also a big possible cause of leaks. Here in Spain and in my home country of Holland we just feed all taps onto the mains.
But overall I tend to prefer EU standards rather than BS. The "Schuko" does have a few serious design flaws like the ability to plug it in upside-down so neutral and phase are reversed, but the French have found a solution for that :)
I think many cold water tank system in Britain have been removed in the last 20 years or so, as people install more efficient central heating / hot water systems.
No idea about Ireland.
(Here in Denmark there are switches on sockets. I find it useful on the rice cooker, which doesn't have its own switch and would otherwise need to be unplugged. The other sockets are generally left with the switch "on".)
All appliances in the UK have a fuse where they connect to the building wiring, normally in the plug, but can be in a fixed fuse-holder like this device. Somewhere in the process it was recognized that having lots of different fuse values would be confusing and awkward for users, so these fuses are the same size and always one of three standard values: 13A, 5A, and 3A. As noted elsewhere, you can buy these particular fuses in UK supermarkets and convenience stores.
If 3A is too high for the appliance then what the designer has to do is to fit it with a flex rated at 3A so that is protected by the fuse at the plug-end and then add additional, lower current, protection at the device end.
The UK system is clever and has subtle details like the standard fuse values which were good at the time it was introduced. But, it is also rather over-engineered, and not optimized for modern homes that have a lot of low-current appliances.