Not sure of the documentation. There have been discussions in the Forum. Too obvious to explain!
Step 1: Open directory containing images. Highlight ones to use.

- 1 Select Images.jpg (47.72 KiB) Viewed 297 times
Step 2: Drop into open FC font at first position.

- 2 Drop into 1st Empty Cell.jpg (70.29 KiB) Viewed 297 times
Step 3: Release mouse.

- 3 When Done.jpg (73.4 KiB) Viewed 297 times
I included the Comma (placed into colon cell) to show you can select individual images. They are loaded in sequence. You would move them into their correct cells afterward.
They tend to group into sets so it goes quickly -- 0-9, A-Z, a-z and individual others.