Thomaz2Fast

You are in spectator mode.

Is Chat option on 'show'?
Option > Mutliplayer Settings > Chat

You are using wrong systask/output
Clear & give command has not the same outputs.

Use:

/clear @p writable_book 0 1 {display:{Name:"Name"},pages:["Text"]}

/clear @p writable_book 0 1 {display:{Name:"Name"},pages:["Text"]}