Brief list of the most important DBeaver shortcuts.
Of course you can redefine any (or almost any) of these shortcuts, here is the list of the default values.
Most of the following commands are accessible from DBeaver main menu, context menu or editor toolbar (or from all of them).
Use context menu wherever it is possible - it usually shows all actions accessible at this moment.

SQL Editor

Shortcut Action
CTRL+Enter Execute current query (*)
CTRL+\ Execute current query in a new tab
ALT+X Execute current script (**)
CTRL+ALT+' Execute selected SQL expression and print results
CTRL+SHIFT+E Explain current query execution plan
CTRL+ALT+SHIFT+X Execute queries of current script simultaneously, showing results in separate tabs
CTRL+9 Switch active connection (for SQL script)
CTRL+Space Option+Space SQL completion proposals popup
CTRL+ALT+Space SQL templates proposals popup
CTRL+SHIFT+F Format current script (**) using current formatter
CTRL+/ CTRL+SHIFT+/ Toggle single/multi line comment
ALT+Up ALT+Down Jump to previous/next query
CTRL+6 CTRL+SHIFT+6 ALT+6 Toggle editor/results panels (maximize/minimize/switch)
CTRL+SHIFT+X CTRL+SHIFT+Y Convert selected text into upper/lower case

Data viewer

Shortcut Action
TAB Switch to record/grid mode
CTRL+~ Switch presentation (grid, plain text, json ,etc)
CTRL+1 Foreign keys navigation menu
ALT+Space Navigate to the link in active cell
ALT+Left Navigate backward in history
ALT+Right Navigate forward in history
CTRL+2 Toggle sorting by current column
F11 Current column filters menu
CTRL+F11 Current column filter dictionary panel
F7 CTRL+7 Toggle right panels on/off
F5 Refresh results (re-run query)

Data editor

Shortcut Action
Enter Activate inline editor
SHIFT+Enter Open value editor dialog or separate value editor (for LOB values)
Delete ALT+Delete Delete row
ALT+Insert Add new row
CTRL+ALT+Insert Copy current row
Escape Cancel changes in current cell/row

Database Navigator

Shortcut Action
F2 Rename current element (if supported)
F4 Open editor of selected element(s)
F5 Refresh selected element(s)
Delete Delete selected element(s) (if supported)
CTRL+ALT+SHIFT+D Add bookmark on selected element
Alt+Enter Show properties of selected element
F3 CTRL+[ Open SQL editor for current connection (***). Shows script selector popup.
CTRL+F3 CTRL+] Open new SQL editor for current connection (***). Always creates new script.
CTRL+Enter Open recent SQL editor for current connection (***). Opens last modified script or creates a new script.

Other

Shortcut Action
ALT+~ Shows database tools context menu
CTRL+0 Switch active schema/catalog (available if SQL/database editor is open)
CTRL+SHIFT+C Advanced copy. Works in different contexts and performs "smart copy" operation (usually with parameters).
CTRL+SHIFT+V Advanced paste. Same as "smart copy" but for "paste".

References

* - Current query is the query under cursor or the selected text. Query is separated from other script queries by delimiter (; by default) or by empty lines.
** - Current script is a set of all queries in the current SQL file. If there is a text selection then only queries in this selection are processed. Queries are separated from each other with a delimiter (; by default).
** - Current connection detected from active window and selection. If active (focused) window is SQL editor or database object editor then current connection is the same as in this editor. If active window is database navigator then active connection is "owner" connection of currently selected element. In other cases there is no current connection and DBeaver will ask you to choose connection explicitly.