Mini tarot decks can be very useful in ones practice. Whether you are just a tarot reader or use it in some sort of ritual mini decks can, I believe, just as much impact as regular sized decks. Though the images are sized down it can still be a good deck and be good to do a reading. But if you have the mini deck in a regular size you know what the image is.
Mini decks are easier to carry in ones purse, briefcase, or anything you carry that a regular one will not fit or you do not want in. You can put a card in your wallet, if you do daily draws and want to carry it with you throughout the day. Also, if you are not ready to have other people know you read tarot a mini deck could fit almost anywhere. The size of these decks may be helpful to some because it may be easier to shuffle, but when you are reading for someone they may expect you to read with a regular sized deck – tell them adhead of time when using a small one. Again, the smaller decks are just as great as the regular sized deck.
You can find these decks in different place like a bookstore or online.
a small list of site to get a start looking at.