There exist three measures that can be taken to resolve your Vodacom Smart Tab 3G low disk space issue
Go to Settings > Storage > Preferred install location > ...select SD card storage or Phone storage - only note that some apps will not install straight SD card and may refuse to install until the Preferred installed location is altered again
Download and use the app called App2SD - only note that certain apps will not let you move them to SD card using this method
Get root (or root your Vodafone Smart TAB 3G). Doing this lets you install Link to SD which will let you move all user installed apps and bloatware to SD card. This is by far the most effective measure toward resolving low disk space issue.