OK, I'm an even later visitor to your site! Looks great to me, either one. They both have the main pictures there to give you an idea about the general property.
But I was very surprised to see that your thumbnails were jpeg's! Have you tried gif's? They are much smaller files. Pictures as small as "thumbnails" aren't meant to covey all the subtle shades in a picture and even jpag's at no compression (if there is such an animal!) still wouldn't, just not enough pixels there! So most people (IMHO) just use a reduced size gif of the full sized jpeg. Most good graphics programs have a batch method of creating the gif files out of a bunch of jpegs (and even naming them for you - I add "TN_" to the beginning of all mine). Looks like all of yours are the same width anyway, that helps in the process.
As for labelling the thumbnails so people will know what they are; don't assume that
anybody knows
anything! At least use the "title=" attribute to say "Click to see a larger image." Another way is to put a border around them with some text stating the same message. You can do that easily with CSS but since you insist on using tables, you can do it there also!
Just create a gif out of the thumbnails you have and compare the file sizes. That's what controls the speed of a page loading.
On our church site, I tend to use as few jpeg images as possible on most pages. Instead I have links to pages specifically for images from pages specifically for
thumbnails. It takes one more click of the mouse, but no one has to get stuck in a slow loading image page unless they really want to. But that's just the way I do it, there are many others, probably even better!
Jim C.