how many data in Arduino progmem?
To see how much memory is available on your arduino, check the GUI after it uploaded the code: "Binary sketch size x bytes (of y byte maximum)". \$ y-x \$ would be the amount available to place data in. 

Or check the tech specs of your Arduino for the value of Flash Memory. All Arduinos with a 328 offer 32kByte of flash, 2k of which is taken by the bootloader, your sketch may take 4k or so, to be on the safe side I would not store more than 20kByte of data.