Adding a "Re-size image" shortcut to the tool box

There is a keyboard shortcut for Image>Resize>Image Size.

Mac

Option-Cmd-i

Windows

Alt+Ctrl+i

Or if you just want to resize an individual layer use Image>Transform>Free Transform.

Mac

Cmd-T

Windows

Ctrl+T

https://forums.adobe.com/people/Minion+Spaceship+Pilot  wrote Does anyone know if it's possible to somehow add a resize image option to the tool box or set it as a key command?

To batch resize multiple images, go to File>Process multiple files.

There are a few presets in the Actions panel - see image below. Simply press the play button if one of those regular sizes is applicable. Unfortunately it is not possible to record macro's in PSE but you can sometimes find free Actions on-line which can be loaded into PSE via the pull-down menu.