Many website designers seem to assume that everyone has superfast broadband, at least 8Gb of RAM and quad core processors, so they cram a massive amount of content into a single page, while completely ignoring the fact that all of that content will take quite some time to download and a lot of additional time for more basic computers to process.
Yahoo.co.uk's home page has vastly more content (including videos, that will always take ages to load on slower systems) than many computers can reasonably cope with, so it's unsurprising when browsers lock up for a while when trying to load such poorly-designed pages. (Anyone using Internet Explorer could probably go away and make a cup of tea while that page loads, as it's packed with HTML5 content, which Internet Explorer is notoriously slow at handling).
There's probably not much you can do about the problem other than to ensure that you've got the fastest broadband connection available in your area and the maximum amount of RAM installed in your computer. You also need to ensure that you're using a fast web browser. (Although I love Firefox, Chrome can probably load all of that HTML content faster. Don't even consider Internet Explorer!)