Sorry about your disappointment danmand, but "tablets" appear to evolve into a new category of devices different from the standard desktop and laptop computers.
It seems that micro SD card has become the stardard format of memory card slot of the Android tablets. This probably stems from the evolution of tablets from smartphones, where the standard SD card is too big. It also seems that one slot per device is the standard.
It also seems that the only standard data port on most Android tablets is the micro USB (not "mini", one size smaller with a flatter connector). This is also the charging port for many new models. The micro USB connection allows the tablet to be detected by PC as an accessory USB device / drive (ie. acting in "slave" mode). However, NOT ALL tablets allow peripheral devices (eg. USB thumb drive, USB card readers) to be detected BY the tablet itself as an accessory device (ie. the tablet working in "host" mode).
This "USB host" or "OTG" (on-the-go) mode is not available in earlier versions of the Android OS - if the tablet has Android 2.3 (nickname "Gingerbread") OS, it MAY OR MAY NOT be activated. Current tablets in the market such as the Samsung Galaxy Tab Plus or Asus Transformer, equipped with Android 3.2 (nickname "Honeycomb") or 4.0 (nickname "Ice Cream Sandwich" or "ICS"), should have this OTG function by default.
Regarding your requirement for viewing pictures on the SD card from your camera:
(1) If the tablet has OTG function, you need to buy a micro USB (male) to standard USB (male) conversion cable, and a mobile USB memory card reader where you plug in your standard SD card. Unfortunately, my experience told me that, for some reason, NOT ALL hardware such as card readers (amongst other things) are compatible with the OTG function. There is no particular brand or model to avoid. Thank goodness card readers are dirt cheap.
(2) You can use micro SD memory cards on your camera - just about all micro SD cards come with a standard SD card adaptor. You can use the micro SD card with the standard card adaptor in your camera. The tablet will be able to read the micro SD card, but it is a tiny little card which is difficult to insert and remove from the slot, and it is easy to lose.
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P.S. I don't know if you use a D-SLR or not, but the standard picture viewer in Android cannot read RAW files. Typical JPEGs are OK. There are Android apps which can read and convert RAW files. If you don't know what I am talking about, just ignore this addendum because you are fine.
