Much of the cursive writing on the slate appears to be written in what is known as "secretary hand," the main form of cursive handwriting taught in Elizabethan England. An expert in the script from the Folger Shakespeare Library has been able to identify the words "Abraham" and "book" as well as some individual letters. She hopes to be able to read more once finer images are produced.
Of particular interest are two marks that resemble characters in a phonetic Algonquian alphabet invented in 1585 by Thomas Hariot. The 36-character alphabet survives as a manuscript in the library of the Westminster School in London; there are also documented references to a dictionary of the Algonquian language some scholars attribute to Hariot. It is conceivable that European explorers arrived at Jamestown with the dictionaries, ready to communicate with the native people. Based on various evidence, curators believe the tablet may have belonged to William Strachey, the first secretary of the Jamestown colony, who arrived there in spring of 1610.
Additional tests and imaging should reveal additional secrets from this extraordinary find. You can view images of the inscriptions at the National Geographic site.
[Original article by Paula Neely.]