What does the cryptic crossword clue "Table of numbers has key error caned sadly (5,8)" mean?

The wordplay uses an anagram. anagram of KEY + ERROR + CANED = READYRECKONER The answer is READYRECKONER.

Table of numbers has key error caned sadly (5,8)

Daily Mail Cryptic #17263 | 15 Across | 2024-01-03 flower