EssentialPIM Free makes extensive use of shortcuts. Here is the list of them:

Global:

Ctrl+Alt+S Minimize to system tray

Shift+Ctrl+T New task

Shift+Ctrl+O New To Do

Shift+Ctrl+N New Note

Shift+Ctrl+C New Contact

Switching Between modules:

Ctrl+0 EPIM Today

Ctrl+1 Schedule

Ctrl+2 To Do

Ctrl+3 Notes

Ctrl+4 Contacts

Ctrl+5 Trash

Database operations:

Ctrl+N New Database

Ctrl+O Open Database

Ctrl+S Save changes or New Database

Ctrl+P Print

In each module:

Ins Adding new element

Del Deleting the element

In Schedule:

Ctrl+D Day View

Ctrl+W Week View

Ctrl+M Month View

Ctrl+Y Year View

Ctrl+E Table View

Ctrl+T Today

Ctrl+G Go to

In To Do:

Ctrl+H Hide/show completed

Ctrl+K Save as Task

In Notes:

Ctrl+R Add to root

Ctrl+Alt+Right  Move in

Ctrl+Alt+Left Move out

Ctrl+Alt+Up Move up

Ctrl+Alt+Down Move down

while creating a new Note

Ctrl+D insert current Day

Ctrl+T insert current Time

In text editing standard shortcuts are enabled: Ctrl+X, Ctrl+C, Ctrl+V, Ctrl+Y, Ctrl+A.

All shortcuts could be edited in Tools -> Options -> Shortcuts dialog.