Right-clicking on a card (ctrl-clicking for Mactintosh users) will give a list of options that can be set for each card. These options are:
Save Target Quantity Changes This saves any changes you have made to the target numbers, which set how many of a particular card you want for trading purposes.
Mark all cards over 4 for trade Affecting all cards, if you own more than 4 of a particular card, this marks all of that card after the fourth for trade.
Mark all for trade Affecting all cards, this marks all cards in your online collection available for trade.
Mark none for trade Affecting all cards, this marks all cards in your online collection unavailable for trade.
