ESP32 processor can support PSRAM, and so far I had seen boards or modules with up to 4MB RAM, but if you need more memory, Espressif Systems has now launched ESP32-WROVER-B module with 8MB SPI PSRAM.

ESP32-WROVER-B module specifications:

WiSoC – Espressif ESP32-D0WD with dual core processor up to 240 Mhz; 5x5mm package

Connectivity 2.4GHz WiFi 802.11 b/g/n up to 150 Mbps Bluetooth 4.2 LE Two antenna designs: PCB antenna or IPEX connector

External Memory – 8MB SPI Pseudo Static RAM (PSRAM)

Storage – 4MB external SPI flash

I/Os – Capacitive touch, SD card interface, Ethernet, SPI, UART, I2S, I2C, GPIOs, VP/VN, etc…

Power Supply – 2.7 to 3.6V

Dimensions – 31.4 x 18.0 x 3.3 mm

Certifications – FCC/CE-RED/IC/TELEC/KCC/SRRC/NCC

ESP32-WROVER-B should be software compatible with other ESP32 modules. It works ESP-IDF framework based on FreeRTOS with LwIP ( light-weight Internet Protocol). TLS 1.2 hardware acceleration is built-in, and secure OTA firmware upgrade is supported. You’ll find more technical details in the datasheet.

I could only find it for sale on Mouser right now, where it goes for $4.20 per unit (minimum order 650 pieces), but it should soon pop-up on most stores where you can purchase other ESP32 modules.