How to manually cache part of someone else's site?

Question

caching

There is a site on which you often have to communicate, but because of the settings on the other side, it takes 20 seconds to load.
How to cache its pictures, scripts so that they are not loaded again every time?
Or cut them out altogether? Or specify which part of the code or which files not to download.
Like robots, but only for my browser.
For example, there is a background image of 300kb, advertising banners of 70, etc.

Answer 1

Adblock can block unnecessary pictures and blocks. In theory, images should be cached anyway, if you have not disabled this in your browser settings.

Answer 2

try handycache proxy server, set locally and specify proxy in browser, cache images/pages