In the art classes I took in college, I did a series of projects where I hollowed out fruits and vegetables in different ways, then lit them from the inside, often with a compact fluorescent bulb to get light but not heat. I worked with eggplant, melon, purple onion, and pineapple. But all of these organic creations quickly became soft. They were more appropriate for creating an exciting photo than for making a glowing object for an event.
The clear winner is the classic, the winter squash.
The photo here is of a warty pumpkin. I took a large spoon and scraped the flesh from the inside until it was thin enough to be translucent, so there would be a general glow from the single candle inside.
I then took a screwdriver and punched holes in it, often nestled in the clusters of bumps on the pumpkin’s surface. No carved face, and no other carving technique besides punching holes. The light shooting out made a nice pattern on the table and had a pleasing look from near and far.