Check the Lumix manual to be sure that they format the card as FAT32 (or exFAT if it's larger than 32GB). If they don't, the tablet can't recognize it, so use whatever software Panasonic supplies to copy the pictures to a PC, then copy them from the PC to the tablet. (Don't just format the card for the phone - that deletes all the pictures.)
Or - if it's the DMC-G7, see page 295 (through to page 298) in the manual. If it's a DC-GX950, start reading at page 63 (and continue on to page 66). (If it's another model, look through the manual for directions on transferring pictures to an Android phone/tablet.)