Do you mean one like this?
JML Energy Efficient Portable Halogen Oven | very.co.uk
(Just shown as an illustration)
Despite having a gas range cooker, which I wouldn't be without, I also have a tabletop halogen oven. I love it as you don't have to wait for the HO to heat up like you do with a conventional oven so cheaper to run and faster, it cooks and heats up almost everything (I haven't tried baking as I usually batch bake). I love it for roasting a chicken if I'm not using the big oven for other things and it's useful as an extra when you are feeding the five thousand. I wouldn't be without it
Three points to consider if buying one:-
1. Try and get one that has a replaceable halogen bulb (not all of them do)
2. Try and find one that has a hinged lid. The stands that come with the removable lids are a PITA.
3. Keep it out on the counter as if you keep it in a cupboard you'll never get it out and it's only useful if you use it.
The extended ring and the tongs are useful. Some makes of HO supply these as standard with the oven, others make you pay extra.