My 8GB tablet keeps warning me that it's low on space. Storage is 96% used with 293MB free. There is almost no data on the tablet and I've installed only 2 apps (93MB & 38MB). I've added a 30GB SD card but it's empty! It seems that most of the apps on the tablet can't be deleted and I can't find a way of moving them to the SD card. Help please!
8GB is an extremely tiny amount of storage space by today's standards. And most likely the firmware itself is using a majority of that space. Cached data taking up some of what's left, leaving behind a very tiny amount for apps. Unfortunately there's nothing you can do about that apart from flashing a custom ROM (plenty of info online on how to do that). This will reduce the firmware size, presuming you download a lightweight style one, giving you a little more space, maybe 1GB.
Maybe, just maybe, you might have the setting available to store some apps on the SD card. If that is possible then you will have to first enable it in developer settings (this is a hidden menu, again Google this to find out how). Then find the app, press and hold, click "app info", then in that menu there should be an option to "Move to SD card", if that option isn't there or its greyed out then there's nothing you can do other than doing option 1 of flashing a custom ROM that does have the move to sd card feature.
My recommendation, buy a new tablet with atleast 64GB free. Even the cheapest current Samsung tablet on the market will be absolutely miles better than what you have now.