I feel bad just giving you a few, but I hope you will get some use out of them.
There are just a few here, but please use them if you like.
ーI feel bad just giving you a few, but I hope you will get some use out of them.
「少しだけで恐縮ですが、(マスクが)役に立つと良いです。」
I feel bad を使って「恐縮です」を表現できます。
get use out of ... で「〜を利用する・〜が役に立つ」
ーThere are just a few here, but please use them if you like.
「ちょっとだけですが、よかったら使ってください。」
just a few「ごく少量・少しだけ」
ご参考まで!