Edge of the table shelf

I have a small table that I eat at, and I also have my mouse and keyboard, I needed a place to set extra stuff so I made a small shelf that's bolted to the edge of the small table, I decided to use some metal brackets that I found in Walmart at the hardware area to reinforce the shelf, it seemed fine without the metal brace for "light" stuff, but I wanted to make sure.

I have yet to print or test the smaller table shelf.

The dimensions are shown in the images.

I included an image of t