What's the correct name for an "association table" (a many-to-many relationship)

There is no "correct" name, but the academic name would be an "Associative Table" (see See the Wikipedia article Associative Entity). Other common names are (in alphabetical order):

• Association table
• Bridge table
• Cross-reference table
• Crosswalk
• Intermediary table
• Intersection table
• Join table
• Junction table
• Link table
• Linking table
• Many-to-many resolver
• Map table
• Mapping table
• Pivot Table
• Pairing table
• Relationship table
• Transition table

Note: This is contents original created by Derek Greer but that was posted as an edit to an accepted answer that totally changed the answer.

Cross reference table. CustomerProductXRef.

"Correct" depends on the modeling methodology in use. I am familiar with Chen, in which this table is the physical implementation of an Associative Entity. I suppose most popular would be directly related to most popular modeling methodology.

Wikipedia lists several names for this type of table.