Looks like the assertion is correct -- <noscript> cannot be used inside a table, according to W3C specs.
Google has said, though, that they don't tightly follow W3C conventions because nobody on the Internet does and they'd miss out on too much if they insisted on full W3C compliance to process a page. My guess would be that they'll still read and process content within a <noscript> tag inside a table.
Your other question, about the Summary attribute, falls under a different General Principle of Google: invisible content is likely irrelevant content. As opposed to <noscript> content, which may be presented to users on occasion, a summary attribute will never be visible. Google appears to heavily discount anything of that nature -- they only want to count what the end user sees.