Do not forget that Odysseus plans "death and destruction" for all the suitors. In general, they are a group of despicable characters.
When Penelope solicits and entices marriage gifts from the suitors, she has a double purpose in mind. First, she wishes to keep the suitors off guard. Second, she wants to prove her loyalty to her husband, whom she has correctly suspected as the disguised stranger.
With the help of enhanced beauty from Athena, Penelope accomplishes what she sets out to do. The suitors are in a general state of complacency and self indulgence. She asserts power and intelligence when she entices them into desiring her more and further tricks them into giving her gifts. In so doing, she proves she has these men under her control.
Odysseus is both pleased by his wife's loyalty and proud of her ability to put the suitors into a weaker position for his surprise attack.
Odysseus is a character famous for his acts of quick-thinking and intelligence, achieving his objectives not necessarily through brawn but definitely through brain. These are qualities he has displayed throughout The Odyssey and indeed in The Iliad. Let us not forget that it was he who came up with the idea of constructing the Trojan Horse that eventually brought about the downfall of Troy. Therefore, in this Book, when Penelope seizes upon an opportunity to outwit and take advantage of the suitors because of her goddess-given beauty, thanks to Athena, the disguised Odysseus is quick to appreciate the same kind of skills and talent for quick-thinking that allows her to show herself superior to the strong, but perhaps rather dim suitors that surround her. In a position of weakness she still shows her strength. This is why Odysseus approves of her actions in gaining more gifts from the suitors.