You can create a panelized array in Altium, but as Klaus recommended, it is usually easier to have the PCB manufacturer panelize it for you. That way they can optimize the array for their tooling, processes, and panel size. You may wish to specify how they are attached (mouse bites, v-groove, etc.) and depending on the size of the board, you may also wish to add assembly rails or leave them in a panelized array for ease of assembly.
Here's some info on Altium's array function if necessary...
**broken link removed**