5 inch TFT LCD for Arduino
You need a driver board to run it. SSD1963 based ones are popular and are often included on the screen, especially the 7" ones on eBay.

Arduinos cannot drive a display directly. Small TFT screens often include the driver chip on them in the form of a Chip On Glass (CoG). That can't be done with the larger screens due to the sheer​ amount of memory needed to store the frame buffer. So an external chip has to be used, or a microcontroller with built in TFT interface.

Note that even with an SSD1963 (or equivalent - see the ones BuyDisplay sell are based on the RA8875) interfacing the Arduino to the TFT screen results will most likely be somewhat disappointing. Especially if you are interfacing using SPI or I2C which will create a bottleneck. Best is to interface with a 16-bit "8080" interface (16 data bits, read, write, chip select, reset and D/C), however that takes a lot of IO pins, and ideally a proper parallel interface to drive it quickly. And you want a lot of RAM for manipulating the data you want to display...