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Doesn't come with a bulb, but yes. You could go as far as just a pair of alligator clips to just connect/disconnect from the battery as you wish.

You can get 10 of these very similar units...

If you do a search in trademe for halogen under the building & renovation\electrical & lighting the fittings that come up will take the MR16 LED's.

eg Display lighting fixture | Trade Me

The MR16's are quite small and have a similar output to your torch. You can get all sorts of colour tints and beam angles. Basically 4x 3W will draw 1A form your 12V battery, so your battery will...

Hmmm. I'd either suspend a couple of lengths of aluminium channel with LED strip like above over the table or some MR16 spotlights. The advantage of the strip is you can control the colour and light...

You could go for strip light like this. About half way down there is a video.

72W Waterproof LED Strip Light RGB 4500lm SMD 5050 - EU Plug/AC 100~240V (5m) - Free Shipping - DealExtreme
...

I'll hunt some stuff out for you.

I'd be tempted to grab a multi-coloured strip light and controller and run it off a 12V car battery. You can basically dial up the colour and light intensity you want on the controller.