There's a very good possibility that mobile/cell phones and tablets would survive high yield EMP blasts with two caveats -
1. they'd need to be in buildings with metal frames or concrete (which typically has a frame of metal reinforcing through it) but isolated from contact with the building itself
and
2. they could not be connected to the electrical grid i.e. using their charger, connected to a computer etc. etc.
The following pages are useful as a start point regarding EMP: -
https://www.askaprepper.com/emp-myth...nd-whats-true/
https://www.askaprepper.com/7-things...urvive-an-emp/
https://containerauction.com/read-ne...ulse-emp-blast
I found this quite interesting even though the EMP generator being used is not particularly powerful. You could probably safely assume that given decent protection from low level EMP, mobile devices (including handheld electronic games) would still be usable in some capacity.
https://www.youtube.com/watch?v=8uIMs8Ye7YY
This video is more informative and the EMP source is more powerful than that used in the video above.
The author tests a variety of phones so as to cover the different generations i.e 1G up to 4G but again, given even "decent" protection, 1990s to 2000s era electronics would be usable in some capacity after an EMP attack. Electronics from around 2010 onward also have a decent chance of being usable depending on the device, for example newer Samsung phones are well shielded because they use EM sources to recharge and don't want the recharging process to mess up the phones electronics.
https://www.youtube.com/watch?v=66ZwuNoNgx4
It's also worth mentioning that modern aircraft (i.e. those that use electronic systems) are actually pretty good at surviving EMP because they have to be shielded from direct contact by lightning strikes. So electronic devices in aircraft have a very good chance of surviving - I mention this because it makes aircraft a potential source of more than just AvGas, metal parts and passenger seats!
According to tests done by an American commission on EMP, cars built before 2002 have a very strong likelihood of surviving EMP as do any devices inside them (as long as they aren't connected to any wiring or in contact with metal surfaces). So like aircraft, vehicles are a potential source of more than just fuel and metal parts.