To use a more modern browser you will need to upgrade to Panther 10.3 or Tiger 10.4. What model iMac do you have? How much RAM & what size hard drive?
You might look over this list of browsers for 10.1. May be one that works better. Mac Web Browsers, Present and Past
http://darrel.knutson.com/mac/www/browsers.html
However, most web page designers "assume" that viewers have modern browsers & use current versions of Flash and other plug-ins.
Cheers, Tom 😉
