you may have to use more light or different light sources. overall thats not bad.
you could try daylight, sunlight is great for photos, especially on a nice wood table or rocks.
the light tent you have is suppose to difuse the light, thats what its doing, but your light sources may need to be re-positioned, add more, or change the ones you have. There is a photography section on the forum for more questions and answers you have (tho i couldnt find it sadly)