iPad 和平板上的 eSIM：和手机比有什么不同

No. The hardware for connecting to a mobile network is simply not present; it is not a software or settings matter. The practical alternative is sharing from your phone by hotspot, which for most uses gives the same result and needs no second plan.

No. One eSIM profile installs on one device at a time. To have both online on their own plans you need two profiles. The cheaper route is one plan in the phone shared to the tablet, where the plan's terms permit sharing.

Generally not, and removing a profile usually means it cannot be used again. Reinstallation terms vary by supplier, so decide which device it belongs on before installing, and read the plan's terms on reinstallation.

There is no single answer, because it depends on what you do. Reading documents and email costs very little; watching video on a large screen costs distinctly more than the same video on a phone. A better method is to look at the tablet's own data statistics for a week at home and use that as your baseline.

Most cannot, and most travel plans are data plans without a number that ordinary services will message. Plan on the phone receiving codes, and where possible set up a backup verification method before you travel.

Buying and installing before departure is considerably easier, because installation needs a connection and doing it on familiar Wi-Fi leaves time to fix problems. Just check when the plan's validity starts counting, since that condition varies between suppliers.

Yes, by hotspot if the plan allows sharing, but the same profile cannot be installed on two devices at once.

Use hotspot from the phone. In practice the result is the same and no second plan is needed.