All if all you've asked largely subjective questions.
The time it takes to load a website is determined more by the files that are needed to load by the client (images / scripts / css) the types of HTML elements you use are negligible. If you're getting to the point where you need to question the performance of actual HTML tags then you're probably doing something wrong.
Which one is more beautiful? Well, that's a silly question --- no one SEES which HTML elements you've used unless they look at the source code. The way your website looks is more determined by the CSS you use. But using DIVs is better practice, and tables were never designed for website layouts, they were designed for displaying tabular data.
Which one is better? Completely subjective. There isn't a hard and fast rule to making websites. What's your target audience? What look/feel are you going for? There's a lot of questions that need to be answered in order to figure out what the best design is.