The On-Screen popup for keyboard shortcuts is currently limited to:
General / Global Shortcuts
Page / Blog Post Actions
Editor - Block Formatting
- Ctrl + Alt + 0
- Ctrl + Alt + 1
- Ctrl + Alt + 6
- Ctrl + Shift + 7
- Ctrl + Shift + 8
- Ctrl + Shift + 9
Editor - Rich Formatting
- Ctrl + M
- Ctrl + K
- Ctrl + Shift + D
- Ctrl + Shift + A
- Ctrl + Shift + I
- Ctrl + Alt + UpArrow --- Resets the screen rotation in Windows 7 & Windows 10
- Ctrl + Alt + DownArrow --- Rotates the screen in Windows 7 & Windows 10
- Ctrl + Alt + RightArrow --- Rotates the screen in Windows 7 & Windows 10
- Ctrl + Alt + LeftArrow --- Rotates the screen in Windows 7 & Windows 10
Editor - Editing Actions
- Ctrl + Shift + E
- Ctrl + Enter
- Ctrl + Shift + H
Editor Autoformatting - Font Formatting
- **Bold**
- ~~StrikeThrough~~
- *Italic*
- `Monospaced`
Editor Autoformatting - Tables
- |Cell|Cell|
- ||Heading||Heading||
Editor Autoformatting - Emoticons
- (/)

Editor Autoformatting - Autocomplete
Editor Autoformatting - Styles
Editor Autoformatting - Lists
Their is also a "View All Shortcuts" that redirect to https://confluence.atlassian.com/get-started-with-confluence-cloud/keyboard-shortcuts-934720180.html
But THAT page includes the statement "We could give you a list here, but then you'd need to keep referring to this page."... Which is kinda the point of the help-screen redirecting to THAT page!