Check your page and find out those unnecessary stuff.
If those things can help improve your website conversion, keep it. Otherwise, remove it to reduce the loading time.
Browsers take more time to parse nested tables.
This will take longer time to display your webpage.
Replace your inline style setting with the CSS class.
This can greatly save the page size and also improve the cleaness of your webpage.
It is easier to maintain a single style sheet file than maintain many inline elements.
Always resize the image to make it best-fit for webpage.
You do not need high resolution of image for the webpage.
Remove unnecessary space between your tags.
Also, some HTML editors may add additional tag in your web page.
You remove them to reduce the page size.