From my iPad How can I send all my pictures to my email ?

Most email Providers have a maximum attachment limit - which will vary between Providers. By example, Google Mail have a maximum attachment limit of 25MB; most other Provider’s have a much lower limit, typically 10-15MB.

As such, sending large numbers of Photos via email is, for most purposes, impractical.

While you goal hasn’t been outlined, instead of attempting to send a large number photos via email, perhaps consider sharing your photos using a Shared Photo Library.

How to use iCloud Shared Photo Library - Apple Support