我估计是不是你的“作者”少打了一个s?
The writers such as were recommended by him in his speech are known to us all.
这句话的主干是：
The writers are known to us all. 这些作家为我们大家所熟悉.=我们都很熟悉这些作家.
be known to sb 为某人所熟悉
such as were recommended by him in his speech 是插入语,such as是“诸如...”的意思,诸如那些在他的演讲时被推他荐到的作家们
参考译文：这些作家们,比如那些他在演讲时极力推荐到的作家们,我们都很熟悉.