you can have tables in your book, simple ones.
to signify a table, you use the " | " or-bar tag.
then use multiple-spaces to separate the cells. there must be at least 3 spaces between cells.
| table 1 | column 1 | column 2 |
| plain-text | yes | yes |
| x.m.l. | no | yes |
| .html | yes | no |
| .rtf | no | yes |
| no | no |
***
as per usual, you can just use the tag on the first line, skipping it on the subsequent lines, but you must start those subsequent lines with at least 3 spaces.
| table 1 | column 1 | column 2 |
| plain-text | yes | yes |
| x.m.l. | no | yes |
| .html | yes | no |
| .rtf | no | yes |
| no | no |
***
you can also use or-bars to separate the cells.
| table 1 | column 1 | column 2 |
| plain-text | yes | yes |
| x.m.l. | no | yes |
| .html | yes | no |
| .rtf | no | yes |
| no | no |
***
you can even mix up these two approaches.
| table 1 | column 1 | column 2 |
| plain-text | yes | yes |
| x.m.l. | no | yes |
| .html | yes | no |
| .rtf | no | yes |
| no | no |