Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Prismatic Polka Dots Mark II No Background
Source GDJ
Here's a quite bright pink background pattern for use on websites. It doesn't look like a real fur, but it definitely resembles one.
Source V. Hartikainen