I think it means "maruo, won't you lend me your dictionary?" But I'm really confused about the verb ending on かす.
A look at some other posts suggests that it might expand to かしてくるのない. So I would have 'come and lend' (previous sentence says that 丸尾 is sat in a chair, so I suppose 'coming' would be appropriate).
Then I would be left with an 'explanatory の' followed by ない. I've never seen a のない ending before, and I don't see how 'explanatory の' would be appropriate in this context. Please help me to untangle all of this. Thanks