What version of Apex are you working on ?
By "Tab Container" you mean a "Region Display Selector" ?
I am using the template Tabs Container (not sure if that is the same as Region Display Selector). With the Tabs Container, I can place other regions (Tabs Container region as parent) within this region. It creates a look that tabs are being used on the page.
Maybe there is a way to hide all items/regions on a region until that tab/region becomes active.
I am open to any and all suggestions.