Your stitches have a front and a back. Normally we knit through the leg of the loop at the front of the needle. Tbl means you'll knit by putting your right tip into the back leg of the stitch, wrap it and pull it through like normal.
Check out the Glossary tab above. There is video for many stitches.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry