Is it possible to connect a tab E to a P4. Tab E is on the recomended tab list but will Not connect.

Here is the DJI recommended list, the only Tab is a 705C.
When connected to the RC if you swipe down and tap "USB for Charging" then change it to one of the other connections and see if it will connect.

iOS Version v2.8.7.
Requires iOS 8.0 or later. Compatible with iPhone 5s, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus,iPod touch 6,iPad Pro, iPad Air, iPad Air Wi-Fi + Cellular, iPad mini 2, iPad mini 2 Wi-Fi + Cellular, iPad Air 2, iPad Air 2 Wi-Fi + Cellular, iPad mini 3, iPad mini 3 Wi-Fi + Cellular, iPad mini 4, and iPad mini 4 Wi-Fi + Cellular. This app is optimized for iPhone 5s, iPhone 6, iPhone 6 Plus, iPhone 6s and iPhone 6s Plus.
Android Version v2.8.4.
Requires Android 4.1.2 or later.Compatible with Samsung tabs 705c, Samsung S6, Samsung S5, Samsung NOTE4, Samsung NOTE3, Google Nexus 9, Google Nexus 7 II, Ascend Mate7, Huawei P8 Max, Huawei Mate 8, Nubia Z7 mini, Sony Xperia Z3, MI 3, MI PAD, Smartisan T1.

Click unknown sources the type in DJI go apk then side load the app, most android devices work fine even though there not officially supported.