The Flex cache organizes the cached objects efficiently by using a "last-recently-used" policy. This page writes a large filler text to generate cacheable entries. If the byte size of all cached entries is raised up to the maximum byte size for all cached entries, the flex cache finalizes the last recently used entries to resize the cache down to the average byte size for all cached entries:

Cached keys: 138
Cached variations: 739
Maximum size of all variations: 8000000 bytes
Average size of all variations: 6000000 bytes
Current size of all variations: 1981352 bytes

Please refer to the Flex Cache Administration for further details about the cached keys and entries.