As @eastgate has said, you need to quote the table expression so that $Name and $Modified don't get evaluated for the parent note's $Name and $Modified.
However, @mwra's solution (
$TableExpression="Name|Modified") won't work, because it will return the logical OR of each child's $Name and $Modified, which will just evaluate to $Name (unless $Name is empty, in which case it will evaluate to $Modified). The problem here is that
| is getting interpreted as an expression operator, rather than being embedded in the expression string.
You have to make sure everything is quoted properly. This will work:
$TableExpression='$Name + "|" + $Modified';
Note the single quotes around the expression (necessary if you want to embed double quotes in the string).
Given the fiddliness of nested quotations and Tinderbox's rather limited support for escaping strings, @eastgate's solution of keeping the expression in a sample note is a really good one.