I'm very open with it and will discus Tarot, other spiritual ideas, or whatever esoteric topic they wish the same as history, Pokémon, the weather or whatever. Most of my friends know I study and read Tarot ... I'd go so far as to say that all of my friends do. I'm pretty sure that all of my coworkers know as well. In fact most nights, as long as it's a fairly slow night, I'll have one or more Tarot decks out, along with notebooks and the couple of books I carry with me. So, if they didn't know, it's not because of me hiding it.
The thing is, if it's a busy night (and I can usually get a good feel for what it's going to be like as soon as I get to work), or if I have data-entry to do, or whatever, I don't pull my stuff out. But I started studying Tarot around 25 years ago, and it was very convenient for me to study during the Graveyard shifts that I was working. It helped me stay awake and I never let it interfere with my work. So, even when it was all new to me, I never tried to hide it. (Yeah, still working at the same place ... actually since 1985.)
My sister is Wiccan, so she was not only interested, but has asked for a few readings and has gotten a couple of decks of her own and bought one for me. My mom gave me her Tarot deck that she'd gotten back in the '60's and has gotten a few readings from me. My dad was fine either way, though not particularly interested. My brother is a little bit "don't ask/don't tell" about it because of his religion - but his wife has had a couple of readings from me. My wife isn't overly interested (as long as I don't spend too much money
) and her family are all pretty okay with it.
It has been my experience so far that most of the people I run into are moderately to very interested in it when they find out. It probably helps that I live only some 30 miles or so from Sedona, AZ - an extremely New-Agey type of place. A lot of that energy spills over to us as well.
I don't think I've lost any friends over it. Well, none that I can think of. And if someone told me they couldn't be my friend because of the Tarot, I'd figure, they weren't very good friends to start with. I kind of have an attitude of "if you don't like me because of x, y or z, then I hope you have a good life. Besides, I reckon I've gained far more friends than I've lost through Tarot ... because I have friends all over the world through Aeclectic Tarot.
Oh ... and one thought occurs to me about getting packages sent to you when your parents might disapprove of the Tarot; if they ask, tell them it's a video kit so you can produce your own gay porn videos ... then just before they have a complete stroke just say; "no, no ... I was kidding, they're just books on Tarot!" Who knows, it might work in your favor ...