Almost nothing is known of Silvester Tatum.  He is listed in a list of immigrants as being sponsored by Thomas Harwood.  There are also records in the Virginia Land Office Patents and Grants database listing "Selvester Tatuam".   You may view these records on-line, or the following is an extraction provided by M. J. Hoth.

"Tatuam, Selvester 20 July 1635   James City County    100 a. In the County of James. In Martins hundred, adjoining the land of Thomas Smith, Southly upon a branch of Kethes Creek. Patents 1, p 257"

The writing on the actual document is incredibly crabbed and hard to read but it appears the document is actually dated from May of 1634.