SD card multiple read

The code you posted (without code tags) will not infer a ram, because it does not follow the ram template in any way. It is not synchronous and does not have th required registered address.

So when compiling, it tries to build the ram out of logic - and dies when the compiler running out of logic.

Given that this is a rather basic mistake, I assume you are an FPGA newbie? have you been through any VHDL tutorials on the subject? I recommended going through digital logic text books as writing VHDL is not at all like writing software.