It means to be well mannered.

意思是举止得体。

As a middle school student, I hope you can be a well mannered tourist.

作为一名中学生，我希望你能成为一个有礼貌的游客。

After a while they forgot that they had objected to him for he was quiet and well mannered and actually knew something about banking and investments.

过了一阵子，他们便忘记自己为曾经他对产了生反感了，因为他又文明又和气，还真正懂得一些办银行和投资的事。

But they were all well mannered, beautifully tailored, and they evidently admired her, so it mattered little to Scarlett that they chose to live utterly in the present.

不过他们都衣着考究，文质彬彬，显然对她十殷勤，而她觉得无所谓。

The term " lady" (lady) here means a woman with good manners, a woman with grace, a woman who is considered to be well behaved, well mannered.

这里的“淑女” （lady）一词是指有礼貌的女人， 有风度的女人， 被认为举止端庄、彬彬有礼的女人。