This is one of the places where it's unfortunate that our English-text rule for quoting a string to set it off from the rest of the error message collides with SQL's rule for quoting an identifier. Leaving out the outer quotes would be contrary to our style guide, but having them there can be confusing too to people who know SQL well.
I'm not sure if this is a serious suggestion or not: enclose the name of the table, as you would type it in psql, between curly quotes.
So for example:
“table_name”
“"TableNameWithUpperCaseLetters"”
In a context where the curly quotes and surrounding message could be in a non-monospaced typeface and the table name (including double quote marks if needed) in a monospaced typeface this would be more natural.
