Custom editors are a convenient method to quickly insert icons in a cell.
You can pick up to 5 icons and have up to 15 custom editors.
The configuration of a custom editor is done in Main menu > Settings > Custom Editor
First assign a name to the new editor ,(for example, Apples)
Fill the empty icon boxes with your chosen icons, as shown below.

Tap on Done when finished.
This editor is ready to be used in any column, create a new column using Add Column (top right button) .
Select your desired grade type and select the new custom editor (Apples) in Cell editor as shown below.

You can now use the new editor in this column.