Its very difficult to match all the features which you mentioned in your question but still I have found some of the answers to your question which are somewhat similar to your demands and some of the suggestions for your question are mentioned below. Go through the details given below to know the best cheapest tablets.
HCL ME Tab Y2 (Rs. 5K)
You can get this device on various online mega stores but you can get this at the cheapest price on SHOPCLUES.com. It comes loaded with the internal storage space of 8 GB and the external storage space can be expanded using microSD card up to 32 GB so that you can be comfortable to store your data. It offers you a 3G network in very cheap cost. It comes with a large size screen of 7 inches which gives much better view in comparison with many other devices. It supports the resolution of 1024 x 600 pixels which give you a great clear view. It runs on 1 GHz processor with 1 GB of RAM so that it can always give a smoother performance. It has 2 MP of rear camera with LED Flash and a front camera of only 0.3 MP. It is powered by a long continuous usable battery of Li-ion 4000 mAh which allows you to use it continuously for long time.
Great processor to give you a smoother experience
Good storage space to store your data
Voice calling feature
Good battery to give you continuous use for long time
So far I have only find one bad feature and that is for its front camera of just 0.30 MP which can't give you good quality of photos or videos.
HP 7 Plus (Rs. 5K)
It is powered by the battery of 3000 mAh which is considered to be great to give you a long time continuous use. It has a primary camera of 2 MP and a secondary camera of 0.3 MP. It supports microUSB 2.0, 3.55 mm jack for head phones connectivity, OTG support, Bluetooth Tethering, USB Tethering as its some of connectivity features. It is found to be 295 gram in weight. It comes with the dimensions of 192.5 x 122 x 8.15 mm. It comes with a LCD Capacitive Touchscreen of 7 inches with the resolutions of 1024 x 600 pixels which gives you a great clear view to your data. It runs on 1 GHz Allwinner A31s ARM Cortex-A7 Quad Core processor with 1 GB of DDR3 RAM so that it can never slow down. It supports Wi-Fi and WAV, MP3, FLAC (Audio Formats). It comes packed with G-Sensor. It runs on Android 4.2.2 (Jelly Bean) which allows you to enjoy many Android games. It comes loaded with the internal storage space of 8 GB and the external storage space can be expanded via microSD card up to 32 GB. As per my opinion its a great device to buy as it comes with a reasonable price tag and perfect for your light work.
HCL ME Tab (Rs. 4,530)
It is powered by the battery of 3200 mAh Lithium - Polymer which can give you a great advantage to use it for very long time. It has a primary camera of 2 MP with flash so that you can click photos in a clear view and a secondary camera of 0.3 MP. It supports microUSB, Bluetooth v3, 3.55 mm jack for headphones connectivity, SIM Slot and many more as its connectivity features. It has a Capacitive Touchscreen of 7 inch which supports the resolutions of 800 x 480 pixels. It runs on 1 GHz Cortex A8 processor. You will get many things along with the device in its packed box such as USB Cable and OTG Cable, V1 Customized Carry Case, Tablet, Noise Cancellation Earphone with Mic and Button and CE Certified Charger so as to comfortably use this device. It supports voice calls and 2G,3G network. It supports Wi-Fi. It runs with 1 GB of DDR3 RAM so as to give you a smooth performance. It comes packed with some sensors such as G-Sensor and Proximity Sensor. It runs on Android 4.0.4 (Ice Cream Sandwich) so that you can enjoy many Android games. It comes loaded with the internal storage space of 4 GB and the external storage space can be expanded using microSD card up to 32 GB.
These were some of the tablets which can fulfill your demands which you mentioned in your question. You can buy any of them from various online mega stores at the price tag which I mentioned along with them. I have mentioned them along with their features so that you can also compare it with other devices to know the best one for you.
I find that the harder I work, the more luck I seem to have.