DisplayTool allows you to open extremely large text files - files larger than 10 GB are no problem. Files can also be opened partially. This is described below.
First open the "Open very large files" dialog via the 3-point menu:
After you have selected the file via "Browse ...", some information about the file will be displayed. This process can take several minutes because the file is completely traversed.
Now specify which area of the file should be read. The example reads from line 29,000,000 to the end - that is, about 718,000 lines.
Now the shortened file can be saved under a new name.
Content of this page:
With a normal editor, extremely large text and log files often can not
be opened. Although DisplayTool is not an editor, it can display very
large files. Several gigabytes in size are no problem. DisplayTool is
free and works under Windows 7, Windows 8 and Windows 10. Since
DisplayTool automatically displays the end of a text file, it can also
be used as Tail for Windows.
Article: Open large text files