Compressing a JMP (version 6 or higher) data table reduces the size of the stored file. You can still run analyses, assign characteristics, and so on. To compress a data table, click the red triangle menu next to the table name in the table panel and select Compress file when saved and save the data table.
After saving the data table, a compressed icon 
appears next to the data table name. To decompress the file, select Compress file when saved again.
appears next to the data table name. To decompress the file, select Compress file when saved again.In addition, you can configure JMP to always use GZ compression when saving by selecting Preferences > General > Save Data Table Columns GZ Compressed.
Note: The Compress file when saved option only decreases the file size. This command does not affect the memory required to analyze the data. To reduce both the file size and memory required for analyzing, use Cols > Utilities > Compress Selected Columns. See Compress Selected Columns.