You can use irfanview to do this.
It has a split image feature in the Options menu that lets you specify the number of columns and rows you would like, the output directory, and the result image types the image is split into.
It then creates new files with a suffix that differentiates the files.
For example: File.jpg split 3x2 would give File_1x1.jpg File_1x2.jpg ... File_3x2.jpg
I scan lots of 35mm slides this way as it puts 1/3 the wear on the scanner, and scans in 1/3 the time. 12 slides per tray, 4 images of 3 slides. With a slight drop in image quality, it's also possible to scan 20 slides (5 images of 4 slides each) at once by scanning directly on the bed like 8x10 images are scanned. But dealing with 20 loose slides, keeping the bed clean and mitigating dust becomes an issue.
After a film roll has been scanned and split, I use the batch rename feature to rename the files so they have the same numbering as on the slides. That way it's easy to go back and rescan a slide if there's dust in the image.
It also has a handy feature for generating index image sheets from the thumbnail viewer which I print to go with the slides or negs, so it's easy to find the "analog" image from the digital image (and vice versa).
One note of warning. Irfan view remembers entered fields between runs. So, for example, if you enter in the directory to store the split files on one run/roll, and then forget to change it on another run, then you'll overwrite files. This isn't a problem if you use roll descriptive file names like: "John Doe 1957-08 Wedding Roll 1.tif"