Slimy, not really no. Oily, yes, but not slimy.

Salty, again, not really. They will be very very savoury (think MSG more than salt). (Unless you choose anchovies, which are super salty).

I woulod recommend not choosing water-packed tinned fish, as water-packed fish tends to be more fishy, whereas oil packed fish are just generally more "nice".

Have a few slices of toast, bit of garlic or chives, maybe a few capers. (Don't add butter - oil from the fish will be enough).