The midfielder will complete his loan spell at the Rs in the play-offs, bidding for a place in football's most valuable game at Wembley for promotion into the Premier League.
QPR take on Wigan over two legs with the first leg tonight at the DW Stadium and the return at Loftus Road on Monday. Derby took a 2-1 lead in their first leg against Brighton last night.
"It’s down to three games now," said Tom, who made two more appearances at Spurs in August before his switch.
"It will define the season - these games will decide whether or not it’s been a successful season. It’s a great way to be promoted, probably a bit more stressful than automatic promotion, but it’s an opportunity to go and play at Wembley and you can’t really beat that."
Wigan have lost three of their last four matches but have shown their undoubted quality again this season - not least by taking the defence of their FA Cup to the semi-finals, and another Wembley appearance.
"Everyone knows what Wigan are like, a good footballing team whether they they go with three at the back or four, they are organised, play out from the back. They are like a Premier League team in that respect," added Tom.
"We've a strong squad at QPR so anything could happen. Hopefully we'll do the business.
"On a personal level, I'm happy with how it's going. There are so many games in the Championship but I feel I've coped well. Now we’ll have to see what happens in the play-offs and hopefully I’ll play a part."