去留学生家做客时，以下是一些合适的英语表达：

感谢邀请

Thank you for inviting me.

It's very nice of you to invite me.

赞美家居环境

Your home is beautiful!

How amazingly you've arranged the party!

用餐时的礼貌用语

What would you like today？

All the dishes are marvelous.

It can't be more tasty!

Thank you for preparing such a splendid banquet.

表达随意和亲切

Come on, make yourself at home.

Don't stand on ceremony, it's an informal dinner.

回应主人的谦逊

Oh, it's just a simple meal, please don't mind.

I'm sure it's not much to offer.

结束时的礼貌用语

Thank you for having me.

It was a pleasure to visit.

See you next time!

这些表达可以帮助你在留学生家做客时显得礼貌、自然，并且能够增进彼此的友谊。