The numeric keys 0 - 9 are used to quickly select a symbol in your palette. These keys are attached to the first 10 colors or symbols used in your palette.
Use the arrow (cursor) keys to move the selected symbols.
Use shift + arrow (cursor) keys to rotate the selected symbols.
Use the Esc (Escape) key to release the selected symbols.
Use the Del (Delete) key to delete the selected symbols.
Use ctrl+a to select all symbols on the current layer.
Not all keyboard shortcuts works in some browsers, because the keyboard shortcuts are already in use by the browser itself, and don't allow an app to override them with custom actions.
Start now designing your own first pattern!