I can see a 10" being a little too heavy to hold after a while. A 7-8" is at the right weight / size to hold with one hand then switch to another without getting to tired too quickly.
Browsing is tricky as clicking on tiny links take more work, I find I need to do a lot more zooming in on the 7".
Another advantage of many 7"-ers is they can charge from the USB port. If for some reason you also have your laptop with you, you can often plug the tablet into it and it will charge (albeit much slower than from the wall charger), most 10"-ers cannot do that.
Browsing is tricky as clicking on tiny links take more work, I find I need to do a lot more zooming in on the 7".
Another advantage of many 7"-ers is they can charge from the USB port. If for some reason you also have your laptop with you, you can often plug the tablet into it and it will charge (albeit much slower than from the wall charger), most 10"-ers cannot do that.