"すら" means "even".
I will give you an example sentence.
Nowdays, even children have cell phones.
- It means that cell phones are so popular in recent days that almost everyone includes children are using it.
Regarding your sentence "こんな 小さい町ですら", I will give you another example.
Even in such a small city, we can use taxis.
People are usually be able to take taxis in the city.
This small city is not exception; even in this small city, we are able to take taxis.
Hope it makes a sense for you.