You can edit the user preferences in the Preferences dialog. It can be accessed by using Edit->Preferences....
Figure 5.1. General Preferences
Default Layout
The layout file to use when opening a new tab. If it is left empty a default will be used.
If it is checked, Bless will try to use the layout of the currently active tab for new tabs. If there are no open tabs, Bless will use the file from the "Layout File" preference.
Undo
Limit the number of actions that can be undone to X actions.
Don't limit the number of actions that can be undone.
Misc
Whether patterns matching the selected range of data will be highlighted in the Data View.
The edit mode new tabs will be placed in (Insert or Overwrite).
Figure 5.2. Session Preferences
Whether the previous session (the state of Bless at the time of the last quit) should be loaded on startup. The state includes all open files, the focused tab, the focused area in each file, the cursor position in each file and the window geometry.
Ask before loading session on startup.
Whether Bless should remember and restore the position of the cursor in each of the loaded files when loading the previous session.
Whether Bless should remember and restore the window size when loading the previous session.