This is a normal way to politely ask a question. Sometimes we use ‘were’ when ‘would be’ is actually more correct.

Hi Andrej, this is one of the options to ask for something in a polite way. English and American cultures are very indirect. Meaning, if you are able to soften your questions and requests - do it as much as possible. Just compare: 1. Are you free for a call on Monday? 2. "I was wondering if" you were available for a quick call on Monday? Which one sounds friendlier and more pleasant? The first one is too direct (that sounds fine for people from Post Soviet Countries, but not for native English speakers.) There are various options how to sound polite such as "would you mind", "is there any chance", "I wonder if you could", "could you please", "do you mind if", etc. FYI if you are interested to learn more about this let me know. I'll be more than happy to help, since I have spent plenty of time learning such cultural differences in the States.