Pattern can be found in the Antique Pattern Library here: https://www.antiquepatternlibrary.org/pub/PDF/H-KB001.pdf

No. 100 Crochet cotton, no yardage specified, no hook size, no gauge.

Filet crochet according to chart. Directions for specific stitches are detailed in instructional section.

p - picots: Are usually made by a chain of three or five, then a slip stitch in the first chain. Where there is a variation of the above, it is specifically given in the directions
sp - spaces: Are the open meshes of filet crochet. To form a space, make one treble, then chain two, skip to stitches of previous row and make another treble. This should result in a perfect square but perfection requires persistent practice as well as the correct sizes of needle and thread. For a space at the beginning of a row, chain five, which allows three for the treble on the edge, and two for the usual chain, two at the top of space.

bl - blocks: Are formed by working trebles in adjoining stitches for the required number. Where blocks are consecutive there are four trebles in the first block and three trebles in each following block. Therefore to find the number of trebles in a row of blocks, multiply the number of blocks by three and add one; in two blocks there are seven trebles, in three blocks, ten trebles, etc.