For explicit loading EF Core offers (from docs):

var blog = context.Blogs
        .Single(b => b.BlogId == 1);

context.Entry(blog)
        .Reference(b => b.Owner)
        .Load();

If I have, for expample, list of 10 entries, I need to 10 times call Reference(...).Load() in foreach, that generate 10 SQL queries to DB.

How about optimized method Entries():

var blogs = context.Blogs
        .Where(...)
        .ToList();

context.Entries(blogs)
        .Reference(b => b.Owner)
        .Load();

which make a single SQL query like: select .... where [BlogOwner].[BlogId] in (?, ?, ?, ?, ?, ?)

Sorry, but I have not found similar functionality. Thanks