In the web application when i click on a link that should load an image from server, it is taking too much time since the images are sized approxmately 3MB - 5 MB, we are un
If images are common among several pages, you may use CSS Image Sprite thing, that will reduce the round trips and for faster delivery of image you may use CDN.
If images are random try async loading of Images, this will not kill the UI/UX.
Convert images to png then use them, or you may try new WebP as stated above.