Hi Hayley,
If my reading of your description is correct, your formula in cell I2 will resemble this: IF(I1="","",formula)
Where formula is either a direct reference to the cell on the table from which the fabric details are to be retrieved, or an XLOOKUP formula to find and retrieve that data.
"I only want the fabric and composition to be filled in if another sample is required."
This suggests that if a "Sample 2" is required, it will always be the same fabric as Sample 1. If that is so,
the simplest formula in I2 would be IF(I1="","",F2)
(The "","" in the formula is " " , " " with no spaces between the five characters (two pairs of quotation marks, separated by a comma.
Regarding merged cells: Merged cells can introduce issues in spreadsheet tables. General recommendation is to avoid them where that is possible. In this case, you might find that leaving cells F, G and H as separate cells in rows 1 to 4, setting the text alignment to center in column G, and NOT setting text to wrap in those cells will present much the same view as seen in your screen shot.
Doing so would require putting the formula in J2, and setting the alignment and wrap rule in that column to match the settings recommended for column F.
Regards,
Barry