Steve Jones wrote:
Just bought two of these from Maplin. One I wanted for my computer and
the other I had the idea of using it for my TV. So when TV goes off,
DVD, video and STB go off as well. A pal of mine had a small house fire
from a TV left on standby.

The one for the computer works great. But I am unsure about whether to
try the other on the TV. The problem being that the master socket on the
mains panel is rated at only 5amps. The TV plug has a 13amp fuse and the
power consumption is 150watts. A 13amp fuse seems high to me but I don't
understand the relationship between power consumption and ampage.

The fuse is utterly irrelevant.
Turn the TV round.
You should find a panel listing "240V 50Hz 250W" or similar.
In practice, I'd be extremely surprised if any TV (barring really huge
projectors for 10m screens.) took 5A.