Microsoft SharePoint Server 2010 includes features that help to optimize page loading over a wide area network (WAN). Designing pages to make them as small and responsive as possible complements these performance improvements.
Different techniques are not specific to Microsoft SharePoint Server 2010. General methods that you can use on any Web site are not discussed in great detail in this article. Instead, this article focuses on the features in Microsoft SharePoint Server 2010, elements that are included in the page, and ways in which you can speed up an initial visit to a SharePoint site
Designing pages for quicker downloads (SharePoint Server 2010)
Aryan Nava 