Why not something like:

echo '[{
    "name": "George",
    "id": 12,
    "email": "[email protected]"
}, {
    "name": "Jack",
    "id": 18,
    "email": "[email protected]"
}, {
    "name": "Joe",
    "id": 19,
    "email": "[email protected]"
}]' | jq -r '.[] | "\(.id)\t\(.name)"'

Output

12  George
18  Jack
19  Joe

Edit 1 : For fine grained formatting use tools like awk

 echo '[{
    "name": "George",
    "id": 12,
    "email": "[email protected]"
}, {
    "name": "Jack",
    "id": 18,
    "email": "[email protected]"
}, {
    "name": "Joe",
    "id": 19,
    "email": "[email protected]"
}]' | jq -r '.[] | [.id, .name] | @csv' | awk -v FS="," 'BEGIN{print "ID\tName";print "============"}{printf "%s\t%s%s",2,ORS}'
ID  Name
============
12  "George"
18  "Jack"
19  "Joe"

Edit 2 : In reply to

There's no way I can get a variable containing an array straight from jq?

Why not?

A bit involved example( in fact modified from yours ) where email is changed to an array demonstrates this

echo '[{
    "name": "George",
    "id": 20,
    "email": [ "[email protected]" , "[email protected]" ]
}, {
    "name": "Jack",
    "id": 18,
    "email": [ "[email protected]" , "[email protected]" ]
}, {
    "name": "Joe",
    "id": 19,
    "email": [ "[email protected]" ]
}]' | jq -r '.[] | .email'

Output

[
  "[email protected]",
  "[email protected]"
]
[
  "[email protected]",
  "[email protected]"
]
[
  "[email protected]"
]

This might not fit your actual use case, but instead of creating a single JSON string in jq, just use a shell command group.

echo '{"foo":"bar", "baz":[1,2,3]}' | { echo "My value is:"; jq .; echo "Some other stuff"; }