*pointer @ length

With Xcode 4.3.2,

(lldb) mem read -ff -c 10 `test`

or

(lldb) x/10f `test`

or

lldb) p test
(float *) $6 = 0x0000000100100a40
(lldb) x/10f `$6`

backtick notation allows you to substitute a scalar value (or something that evaluates to a scalar value, e.g. `10+5`) for an argument in lldb commands.  And the "p/" and "x/" shortcuts from gdb are mostly supported.