He is very lucky to have a spacious study like this; there's not room to swing a cat in mine.

他很幸运有这么一个宽敞的书房，我的书房却是非常狭小。

In their old flat they did not have enough room to swing a cat, but now they've got plenty of space.

在旧套间里，他们连活动的余地都没有，现在他们有相当宽敞的地方了。

If your home is very small, you might say there is not enough room to swing a cat. But you probably should not try this at home!

的意思不难理解，连猫都难以行走，说明空间之狭小，根本没有转身的余地。

I agree! There's not enough room to swing a cat.

我同意！连转身的空间都没有。

My new apartment is tiny. There's not even enough room to swing a cat.

我的新公寓很小间，甚至没有什么多馀的空间。