In XnView you cannot achieve this directly, but with some trick you can achieve this. Try the following steps:
If you want to create one large image out of several images, you can use "Tools->Create Panorama". Please note that in XnView, panorama images aren't 360 degrees images but several images merged together to one. XnView aligns the images side by side and merges them to a larger image. You can align the images horizontally or vertically. In the XnView online help, chapter "Create panorama images" you will find general info on this function.
Sample:
E.g. to create a 3x3 image with your passport photograph (see sample above) you have to apply "Create panorama" two times:
1.) First you copy your passport image two times. You can use MS Explorer or XnView to copy the file.
[1]
2.) Then you merge your original image and the two copies horizontally. The resulting image will look like this
[1] + [1] + [1]
Save the resulting image. Since you want to keep good quality, you should save in a non lossless format, e.g. PNG or BMP. (The resulting image might be large, but you will delete it later, again.)
3.) Make two copies of the image that you have just created and saved in the previous step. Again, you can use XnView or MS Explorer for this.
4.) Merge the three images together, this time vertically.:
[1][1][1]
+
[1][1][1]
+
[1][1][1]
5.) Print and/or save your result. When saving, you can use a lossy format like e.g. JPEG.
6.) Last not least you delete the interims files created in step 2.) and 3.)
That's it.
Note: Most of this info is taken from post 'Combine images to mosaic'.