Command:
kbBlockManager
The Block Manager allows blocks to be Previewed, Inserted, and even Swapped! Works on Xrefs too.
Switch to the
Import Blockss to, well, Import Blocks.

This button will switch between listing the current drawings blocks and xrefs.

This button will count the number of inserted blocks for a selected block type.

This button will add a Ceiling Grid Object.

If changes have been to the drawing, blocks created or purged, use this button to "refresh" the Form.
Local Blocks
This list control shows the current drawings blocks (or Xrefs if you've used the toggle).
Preview
After selecting a block from the list, it's preview will be displayed (same with loaded xrefs).