No expert on this but have a 10" tablet. I can connect camera via USB cable or put the
micro SD from the camera into the SD slot on the tablet. Sd slot can also be used for
HDMI cable from tablet to big screen if I wish.
Cost about £160. You can get cheaper ones for around £120 but I wanted a
good screen for a little extra.
It depends on the tablet. An iPad does not have a USB connector but you can get an adaptor which reads the sd card. Other tablets have usb ports often of the micro variety and some have sd card readers.
With tablets you get what you pay for and I suggest that he is at the low end of the budget. Have a look at the Samsung models or Nexus.