You can use an arduino, but not a normal one, you'll need a mega, i say this because the ardiono mega is the only arduino i know of with more than one serial UART. The Uno for example shares the RX/TX serial pins with the same UART as the USB interface.
If you DO have a mega, you can get a cheap USB to Serial module such as this: http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=arduino+usb+to+serial&_sop=15
Now, you plug your PC into the mega's normal USB This will power the Mega from your PC.
Then you connect your tablet to the serial module.
All that's left to do is create a simple ino script for your mega to transfer data from serial (pc-USB) to serial2 (Tablet), and vice versa..
Example:
void setup() {
// put your setup code here, to run once:
Serial.begin(115200); // PC <--> USB
Serial1.begin(115200); // Serial <--> Tablet
}
void loop() {
// put your main code here, to run repeatedly:
serialComs(); // Tells loop to execute the serialComs() function
}
// Serial Comunication function
void serialComs() {
// read from port 1 (Tablet), send to port 0 (PC):
if (Serial1.available()) {
int inByte = Serial1.read();
Serial.write(inByte);
}
// read from port 0 (PC), send to port 1 (Tablet):
if (Serial.available()) {
int inByte = Serial.read();
Serial1.write(inByte);
}
}
NOTE: You may need to add #DEFINE entries before void setup to define which pins are which on your serial to USB module.
