Does the simile ("endearing, sly and suave” book 6 line 162)describing Odysseus as he meets Nausicaa seem appropriate?

Your quote isn't a simile.

Ok,it's not a simile. But what does that quote mean?

Nausicaa has a crush on Odysseus and perhaps Odysseus knows this. In any case, he speaks to her in a way that is "endearing, sly and suave”. Odysseus is pretty confident around women. I suppose it helps that he has Athene in his corner!