Hello Abhishek,
the record count should still be visible via M_TABLES if a table is not loaded or unloaded.
Regarding the size, you can check the estimated size fields (ESTIMATED_MAX_MEMORY_SIZE_IN_TOTAL, LAST_ESTIMATED_MEMORY_SIZE) in M_CS_TABLES, showing you the estimated size memory for a full table load. In that view also the record count (RECORD_COUNT) can be found again.
Regards,
Florian