Modern Candles for sca feasts:
Modern candles are generally made from white paraffin. Many of the yellow beeswax candles available today are deliberately coloured yellow or purified less to keep a yellow colour to distinguish them from paraffin (although sometimes you can get Asian import beeswax candles that are cheaper and whiter, although some may contain part paraffin).
Large fat beeswax candles are good for feasts - you can often buy them cheaply, they are a not bad imitation of period candles, white/cream ones usually don't contain nasty scents that people have allergies to, and they should last nicely, without going out, through several feasts. They also generally keep the light at the height required for seeing your food.
The tall white emergency candles generally require a candlestand, drip wax more, blow out more often and shed less light, but still work quite well. You can generally buy a pack of 10 from the supermarket for just a dollar or two.
Tealight candles, are cheap and provide lots of light, however they burn very hotly, heating up the feast hall, which in the Australian winter is generally quite hot enough by the time everyone arrives (and let's not mention the Australian summer). They also go out easily, wax stain tablecloths (and more permanently than other candle types) and can be hotter to touch. Other types of candles (including the very similar, but less hot votive candles) are much better alternatives for an indoor feast.
TO GET MORE LIGHT FROM YOUR CANDLES: Put a metal(silver or brass)tray under the candles, and stand up another tray behind to act as a reflector. You can get nice cheap metal trays from Woolworths supermarkets and also from those asian discount homewares stores. Square trays stand up easier, but oval works OK. You may already have a tray or two for serving food.