source text context
To see more than a few words on either side of your search-word
you could press (F8) to "grow" all the rows, or (Ctrl+F8) to shrink them. Or Alt+F8 to grow the current line only (Ctrl+Alt+F8 to shrink it).
Stretch the display manually
You can pull the concordance display to widen its column. Just place the mouse cursor on the bar between one column and another; when the cursor changes shape you can pull the whole column.
The same applies to each individual row: place the mouse cursor between one row and another in the grey numbered area, and drag.
View the whole source text-file
(if it is still on the disk where it was when the concordance was originally created)
Double-click the concordance column, and the source text window will load the file and highlight the search word.
Or double-click the file-name column, it will open in Notepad for editing. (If the connection isn't working, re-compute file-lists.)