An E-sheet is a portable computer technology employed in the Twelve Colonies around 58 BCH.
The E-sheet can be folded like regular paper and features a touch-screen interface, complete with an on-screen keyboard. While the extent of its features are unspecified, the E-sheet is capable of wireless communication and features an independent power source, and houses an applications suite that includes an electronic mail client.
External portable media devices can be attached via dongles to the sheet, as Daniel Graystone uses one to capture the code that Zoe Graystone used to create her sentient holographic avatar in the virtual world of the holoband (CAP: "Caprica pilot").
It is surmised that the technology fell into disuse as a result of the First Cylon War, where any advanced technology was abandoned as a result of the Cylons' ability to compromise and turn advanced technologies against the Colonials (TRS: "Miniseries").