Is there a site? No or not really. Box sites are easy - a bottom, four sides and maybe a lid. You can make some fancy boxes, but they are still a relatively well defined problem. Even something as “simple” as a table number is anything but. What font? Many fonts are licensed and even open fonts may have different rules for displaying on the web versus cutting glitter acrylic with them. What base shape? Are you going to make the base out of many layers? Is the base material the same thickness as the number material? Are there more than nine tables? If so how do you support the 1 and 0 of table 10? Like this:
Or like this:
It is the simple things that lead all of us here to learning a program like Inkscape, Adobe Illustrator, CorelDraw or Affinity Designer. Those tutorials the other posters linked in their posts above. To continue the table number example, it is really easy. You make a number, add a tab to the bottom and then union the tab with the number. In your base you cut a rectangular hole that matches your tab. Just like this:
It’s really easy once you’ve learned the program. Learning it can be frustrating. I like to know it can be done before jumping in. So jump in. How hard could it be, I did a simple one in a couple of minutes. Once you have started to master the simple things you can learn about kerf (aka why is the number falling out of the base??) and all the design details you did not know existed. It really is fun and quite rewarding when everything finally goes right. Just don’t learn on your final material, use something cheap at first.