I have created a svg, the exact size of a business card

Now I want to create a A4, containing a mosaic of 8 business cards, in order to print them from a pdf

Create Tiled Clones seems to be the solution, but the problem is that I want to clone the whole card (so the original page, which is 85 x 50 mm), whereas the "objects and texts" take a smaller region. How can I instruct Inkscape to take the whole size?

thanks

You can maybe make a rectangle object the size of the card with no fill and no stroke, and group that with the other objects.

Easily sized with Menu: Edit>Guides around page, if your current image is the size of the card.