Why would a Clustered Index Seek return a higher "Actual Number of Rows" than there are rows in the underlying table?
The Seek returns more rows because it is on the inner (bottom) side of a Nested Loop. Every row returned by the outer operation results in a new Seek operation. So you're not getting 60m rows from a single Seek, but from over 9000 of them (number of executions).

Also of note: when looking at estimations, the total number of rows estimated will be Estimated Number of Executions multiplied by Estimated Number of Rows