Minecraft – Make part of a writable book read only

The current snapshots for 1.8 allow this with a "spectator" game mode. Spectators are always flying, and clip through blocks. As a consequence of this, they also can't land like you would in creative, and will simply clip through to the void if they try. Spectators can also view the world through the eyes of a player or mob, as well as view, but not modify the contents of chests, dispensers, etc.

Of course, being a spectator also means that regular (i.e. survival and adventure mode) players won't be able to see you, and you only appear as a disembodied head to other spectators, but the other features it offers may be worth that cost.

For books what you need to do is add on things called clickEvents after each command. So if you had a command that looked like this:

/tellraw @p ["",{"text":"Tp","clickEvent":{"action":"run_command","value":"/tp @p 100 100 100"}}

This gives you a tp command simply called Tp ("text":"Tp") that teleports you to 100 100 100.

What you would do to add a command is add a comma and start the next line of command:

,{"text":"Tp","clickEvent":{"action":"run_command","value":"/tp @p 120 100 100"}}]

This will teleport them 20 blocks higher then the last command. If we add both commands together the end result should look like this:

  /tellraw @p ["",{"text":"Tp","clickEvent":{"action":"run_command","value":"/tp @p 100 100 100"}},{"text":"Tp","clickEvent":{"action":"run_command","value":"/tp @p 100 100 100"}}]

There are book generators out there that will do this for you without the need to type it out yourself, This is a link to one that is fairly popular and works great: https://www.minecraftjson.com/