Villa, who were beaten 8-0 at Chelsea last weekend, held out Spurs during the first half.
But after the break Jermain Defoe opened the scoring in the 57th minute before Gareth Bale ran riot with a 23-minute hat-trick.
The defeat leaves Villa fifth bottom and with the Premier League's worst goal difference.
Asked if the Chelsea and Spurs losses had come out of the blue after impressive cup and league wins at Norwich and Liverpool, Lambert told Sky Sports News: "I'm not surprised by anything in football.
"Things can happen. You know it can happen, especially when you are playing one of the top sides."
Lambert later added: "We rode our luck massively in the first half - Spurs were very good in the first half.
"I thought we started the second half really well and were in the ascendancy, and I think with the first goal, there is a foul on Fabian in the first place - I think a free-kick should have been given.
"With the second goal we had a good chance to make it 1-1, but they go up the other end of the park and score again.
"That is what can happen when you are playing against these types of players."
Lambert is confident his men will be able to move on from the disappointment of the last few days and find a positive response.
"They will be fine," he said. "Whether we win, lose or draw, they will be fine. We always try to treat them the same way and try to keep their spirits the same.
"One thing in football is that you can't dwell on it and you have to bounce back - there is no other way."