The Talisman FAQ states:

Q: Can a character ditch an Object or Follower after drawing the first card to avoid drawing the second card?
A: Yes. Remember, however, that if a character ditches Objects or Followers he cannot take them back during the same turn.

How is it that the answer is "yes"? Once he starts drawing he is encountering the space. Otherwise he is simply encountering the cards one at a time. Or is it that he draws the card, sees what it is, decides he wants to encounter that card only (say the drawn card is a Dragon and he doesn't want to risk encountering two Dragons at once), ditches an item, and then encounters the drawn card?

He must ditch before encountering the first card, yes.

Osbo25 said:

Basically a character may land on the Ruins where there are no cards, draw 1 card which is say the Holy Lance and then ditch one of his Objects to prevent having to draw a second card. This guarantees a character taking the Holy Lance (see page 9 of the main rulebook for the actual rule).

Ell.