The object cache can be turned on in the settings. When it's on, the plugin will save the results of complex operations and therefore it needn't go through the same process again. The benefit is faster pager delivery and less burden on the server.
The cache mainly affects the rendering of shortcodes. Alternatively, you can use any other plugin that caches the page output. The object cache, however, will still speed up the rendering of identical shortcodes that appear on different pages.