A new tablet study by the Online Publishers Association reveals that tablet adoption continues to skyrocket, now up to 31% of respondents — and a surprising 74% use the device daily. The study (.pdf), conducted with Magid, drills down on usage patterns and other handy facts. It’s a great nuts-and-bolts study to have, and we’ve highlighted TV-oriented data points below:

Tablet users spend an average of 13.9 hours a week on the device, and 5-11 p.m. is primetime. Last week, ABC noted it “parallels broadcast consumption patterns,” so the network tailored its new iPad app to showcase video during the primetime hours.

Of all the activities on the app, watching video comes in first at 54%. Weather and news follow.

Taking a deeper look at video, shorter-form content still rules, spanning news, sports, TV show clips and weather forecasts. Full-length content, however, will probably climb up the list as more compelling content increasingly becomes available for iPad viewing.

And as we all know, second-screen multitasking (85% of the time) — and even third-screen multitasking (66% of the time) — is a natural phenomenon with the tablet. Heavy multitaskers spend as much as 3 hours a day while actively consuming content on several devices.

On the advertising front, such multitasking doesn’t dilute the tablet ad experience. Around one-third of heavy multitaskers in the study said tablet ads motivated them to research and purchase products. Lots more good stuff in the study, which is available here (.pdf.), and here’s the study overview.

Plus: See more social TV research studies