On his birthday feast Tom proposed a toast to his parents.
嗯，不可以用birthday party，因为是宴会。Party是非正式场合，一般你说在party上敬酒有点奇怪
birthday feast就是真正的“生日宴会”
如果想说一个先是宴会，然后又有娱乐活动的，可以说birthday feast party.
关于propose a toast的整个过程，敬酒的动作，详见
http://www.wittcom.com/how_to_propose_a_toast.htm
