Discussion on answer by mirka: why "お食事の際は、..." instead if "ご飯を食べる際は、..."?

Imported from a comment discussion on http://japanese.stackexchange.com/questions/28136/why-%e3%81%8a%e9%a3%9f%e4%ba%8b%e3%81%ae%e9%9a%9b%e3%81%af-instead-if-%e3%81%94%e9%a3%af%e3%82%92%e9%a3%9f%e3%81%b9%e3%82%8b%e9%9a%9b%e3%81%af/28140#28140