I just tested in a fully patched digital download version of DKS, from Amazon, for the PC in the USA and these three methods take all loot from a container:
1. Right-click or press the use key (E by default on PC) and click the Take All button.
2. Press the use key twice; once to open the container and once again to take all loot.
3. Right-click twice; once to open the container and once again to take all loot.
I would like to thank Aleroth's recently deceased for allowing me to test this.
Ah well, my Steam version doesn't give the option. Maybe with the patch that will change?? not loosing sleep over it though, excuse me while I bash head-to-keyboard for being to lazy to go to the store that day
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*Looks over to left at retail edition of Beyond Divinity case, now a coffee coaster** 
