What do these phpMyAdmin errors mean on my WordPress databaes?

As it writes, a problem with the indexes definitions of those tables. Please try a repair on the reported table and see if that helps.

Have you activated a specific add-on lately or did you alter tables?

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)