You can use WinRAR, WiinZip or similar utilities to unpack the .cab file.  However, it's intended for IT administrator to deploy installation over network.  There is a lot easier way to update your system using drivers from here  https://www.dell.com/support/home/en-uk/product-support/product/dell-venue-11-pro-7000-7140/drivers

Note:  system service tag was removed to protect your private information.