How many Gbs you may need is dependent on how graphic intensive the work that you will do on the computer is. When you said streaming video for movies you increased the need considerably. Average 1Gb for each hour of streaming video. 10 Gb a month - just for five movies during that month. Anyone can guess but you need to take an average night of work and see how much data you have used. There are several software applications for a PC that will do this and some are free. Take several night samples and you will know much better how much data to get for your hotspot plan. Also a tablet uses less data than a laptop to do the same online tasks if using a mobile browser not set to desktop mode.